21012415200 has 432 divisors, whose sum is σ = 88406685360. Its totient is φ = 4802595840.

The previous prime is 21012415199. The next prime is 21012415231. The reversal of 21012415200 is 251421012.

21012415200 is a `hidden beast` number, since 2 + 101 + 2 + 41 + 520 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1048474 + ... + 1068326.

It is an arithmetic number, because the mean of its divisors is an integer number (204645105).

Almost surely, 2^21012415200 is an apocalyptic number.

21012415200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21012415200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44203342680).

21012415200 is an abundant number, since it is smaller than the sum of its proper divisors (67394270160).

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

21012415200 is a wasteful number, since it uses less digits than its factorization.

21012415200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19896 (or 19870 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

Adding to 21012415200 its reverse (251421012), we get a palindrome (21263836212).

The spelling of 21012415200 in words is "twenty-one billion, twelve million, four hundred fifteen thousand, two hundred".