21013401600 has 351 divisors, whose sum is σ = 75767233269. Its totient is φ = 5566464000.

The previous prime is 21013401593. The next prime is 21013401623. The reversal of 21013401600 is 610431012.

It is a happy number.

The square root of 21013401600 is 144960.

It is a perfect power (a square), and thus also a powerful number.

21013401600 is a `hidden beast` number, since 2 + 10 + 13 + 40 + 1 + 600 = 666.

It can be written as a sum of positive squares in only one way, i.e., 7564824576 + 13448577024 = 86976^2 + 115968^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 139161525 + ... + 139161675.

Almost surely, 2^21013401600 is an apocalyptic number.

21013401600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21013401600 is the 144960-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21013401600

21013401600 is an abundant number, since it is smaller than the sum of its proper divisors (54753831669).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21013401600 is an equidigital number, since it uses as much as digits as its factorization.

21013401600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Multiplying 21013401600 by its product of nonzero digits (144), we get a square (3025929830400 = 1739520²).

21013401600 divided by its product of nonzero digits (144) gives a square (145926400 = 12080²).

Adding to 21013401600 its reverse (610431012), we get a palindrome (21623832612).

The spelling of 21013401600 in words is "twenty-one billion, thirteen million, four hundred one thousand, six hundred".