21011451055572 has 48 divisors (see below), whose sum is σ = 50355696780032. Its totient is φ = 6813992626560.

The previous prime is 21011451055559. The next prime is 21011451055579. The reversal of 21011451055572 is 27555015411012.

It is a self number, because there is not a number n which added to its sum of digits gives 21011451055572.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011451055579) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3865797 + ... + 7547667.

Almost surely, 2^{21011451055572} is an apocalyptic number.

It is an amenable number.

21011451055572 is an abundant number, since it is smaller than the sum of its proper divisors (29344245724460).

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

21011451055572 is a wasteful number, since it uses less digits than its factorization.

21011451055572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3694768 (or 3694766 counting only the distinct ones).

The product of its (nonzero) digits is 70000, while the sum is 39.

Adding to 21011451055572 its reverse (27555015411012), we get a palindrome (48566466466584).

The spelling of 21011451055572 in words is "twenty-one trillion, eleven billion, four hundred fifty-one million, fifty-five thousand, five hundred seventy-two".