21111212010204 has 36 divisors (see below), whose sum is σ = 53364591997080. Its totient is φ = 7037052285600.

The previous prime is 21111212010193. The next prime is 21111212010223. The reversal of 21111212010204 is 40201021211112.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×21111212010204² (a number of 27 digits) contains 22 as substring.

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 11 ways as a sum of consecutive naturals, for example, 26497254 + ... + 27282354.

Almost surely, 2^{21111212010204} is an apocalyptic number.

It is an amenable number.

21111212010204 is an abundant number, since it is smaller than the sum of its proper divisors (32253379986876).

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

21111212010204 is a wasteful number, since it uses less digits than its factorization.

21111212010204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1532050 (or 1532045 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21111212010204 its reverse (40201021211112), we get a palindrome (61312233221316).

The spelling of 21111212010204 in words is "twenty-one trillion, one hundred eleven billion, two hundred twelve million, ten thousand, two hundred four".