21457513800 has 288 divisors, whose sum is σ = 73615913280. Its totient is φ = 5599756800.

The previous prime is 21457513799. The next prime is 21457513837. The reversal of 21457513800 is 831575412.

21457513800 is a `hidden beast` number, since 2 + 1 + 4 + 575 + 1 + 3 + 80 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 21828109 + ... + 21829091.

It is an arithmetic number, because the mean of its divisors is an integer number (255610810).

Almost surely, 2^21457513800 is an apocalyptic number.

21457513800 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 21457513800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36807956640).

21457513800 is an abundant number, since it is smaller than the sum of its proper divisors (52158399480).

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

21457513800 is a wasteful number, since it uses less digits than its factorization.

21457513800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1253 (or 1241 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The spelling of 21457513800 in words is "twenty-one billion, four hundred fifty-seven million, five hundred thirteen thousand, eight hundred".