21415420432564 has 12 divisors (see below), whose sum is σ = 37477045720800. Its totient is φ = 10707693083768.

The previous prime is 21415420432529. The next prime is 21415420432607. The reversal of 21415420432564 is 46523402451412.

It is a super-2 number, since 2×21415420432564² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21415420432564.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1228624 + ... + 6658855.

It is an arithmetic number, because the mean of its divisors is an integer number (3123087143400).

Almost surely, 2^{21415420432564} is an apocalyptic number.

It is an amenable number.

21415420432564 is a deficient number, since it is larger than the sum of its proper divisors (16061625288236).

21415420432564 is a wasteful number, since it uses less digits than its factorization.

21415420432564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8566262 (or 8566260 counting only the distinct ones).

The product of its (nonzero) digits is 921600, while the sum is 43.

Adding to 21415420432564 its reverse (46523402451412), we get a palindrome (67938822883976).

The spelling of 21415420432564 in words is "twenty-one trillion, four hundred fifteen billion, four hundred twenty million, four hundred thirty-two thousand, five hundred sixty-four".