21055111600 has 60 divisors (see below), whose sum is σ = 51225297760. Its totient is φ = 8315424000.

The previous prime is 21055111489. The next prime is 21055111603. The reversal of 21055111600 is 611155012.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21055111603) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 301551 + ... + 364750.

Almost surely, 2^21055111600 is an apocalyptic number.

21055111600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21055111600 is an abundant number, since it is smaller than the sum of its proper divisors (30170186160).

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

21055111600 is a wasteful number, since it uses less digits than its factorization.

21055111600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 666398 (or 666387 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 22.

Adding to 21055111600 its reverse (611155012), we get a palindrome (21666266612).

The spelling of 21055111600 in words is "twenty-one billion, fifty-five million, one hundred eleven thousand, six hundred".