21112120524 has 96 divisors (see below), whose sum is σ = 57095942400. Its totient is φ = 6010018560.

The previous prime is 21112120517. The next prime is 21112120543. The reversal of 21112120524 is 42502121112.

It is a self number, because there is not a number n which added to its sum of digits gives 21112120524.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 67107 + ... + 216165.

It is an arithmetic number, because the mean of its divisors is an integer number (594749400).

Almost surely, 2^21112120524 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21112120524, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28547971200).

21112120524 is an abundant number, since it is smaller than the sum of its proper divisors (35983821876).

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

21112120524 is a wasteful number, since it uses less digits than its factorization.

21112120524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149143 (or 149141 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 21.

Adding to 21112120524 its reverse (42502121112), we get a palindrome (63614241636).

The spelling of 21112120524 in words is "twenty-one billion, one hundred twelve million, one hundred twenty thousand, five hundred twenty-four".