21011022012 has 24 divisors (see below), whose sum is σ = 49032740736. Its totient is φ = 7002670768.

The previous prime is 21011021989. The next prime is 21011022083. The reversal of 21011022012 is 21022011012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35568 + ... + 208055.

It is an arithmetic number, because the mean of its divisors is an integer number (2043030864).

Almost surely, 2^21011022012 is an apocalyptic number.

It is an amenable number.

21011022012 is an abundant number, since it is smaller than the sum of its proper divisors (28021718724).

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

21011022012 is a wasteful number, since it uses less digits than its factorization.

21011022012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250817 (or 250815 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21011022012 its reverse (21022011012), we get a palindrome (42033033024).

The spelling of 21011022012 in words is "twenty-one billion, eleven million, twenty-two thousand, twelve".