21030461564 has 48 divisors (see below), whose sum is σ = 42870643200. Its totient is φ = 8840838720.

The previous prime is 21030461531. The next prime is 21030461591. The reversal of 21030461564 is 46516403012.

It is a self number, because there is not a number n which added to its sum of digits gives 21030461564.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 364787 + ... + 418485.

It is an arithmetic number, because the mean of its divisors is an integer number (893138400).

Almost surely, 2^21030461564 is an apocalyptic number.

It is an amenable number.

21030461564 is an abundant number, since it is smaller than the sum of its proper divisors (21840181636).

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

21030461564 is a wasteful number, since it uses less digits than its factorization.

21030461564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53978 (or 53976 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 32.

Adding to 21030461564 its reverse (46516403012), we get a palindrome (67546864576).

The spelling of 21030461564 in words is "twenty-one billion, thirty million, four hundred sixty-one thousand, five hundred sixty-four".