21520414204 has 24 divisors (see below), whose sum is σ = 38231685968. Its totient is φ = 10597150080.

The previous prime is 21520414177. The next prime is 21520414231. The reversal of 21520414204 is 40241402512.

It is an interprime number because it is at equal distance from previous prime (21520414177) and next prime (21520414231).

It is a congruent 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, 1814614 + ... + 1826434.

Almost surely, 2^21520414204 is an apocalyptic number.

It is an amenable number.

21520414204 is a deficient number, since it is larger than the sum of its proper divisors (16711271764).

21520414204 is a wasteful number, since it uses less digits than its factorization.

21520414204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18685 (or 18683 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 25.

Adding to 21520414204 its reverse (40241402512), we get a palindrome (61761816716).

The spelling of 21520414204 in words is "twenty-one billion, five hundred twenty million, four hundred fourteen thousand, two hundred four".