21311311023212 has 24 divisors (see below), whose sum is σ = 42858106156320. Its totient is φ = 9082958129280.

The previous prime is 21311311023181. The next prime is 21311311023253. The reversal of 21311311023212 is 21232011311312.

It is a happy 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, 2102531537 + ... + 2102541672.

It is an arithmetic number, because the mean of its divisors is an integer number (1785754423180).

Almost surely, 2^{21311311023212} is an apocalyptic number.

It is an amenable number.

21311311023212 is an abundant number, since it is smaller than the sum of its proper divisors (21546795133108).

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

21311311023212 is a wasteful number, since it uses less digits than its factorization.

21311311023212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4205073401 (or 4205073399 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 21311311023212 its reverse (21232011311312), we get a palindrome (42543322334524).

The spelling of 21311311023212 in words is "twenty-one trillion, three hundred eleven billion, three hundred eleven million, twenty-three thousand, two hundred twelve".