21207239415 has 12 divisors (see below), whose sum is σ = 36759215064. Its totient is φ = 11310527664.

The previous prime is 21207239413. The next prime is 21207239437. The reversal of 21207239415 is 51493270212.

21207239415 is a `hidden beast` number, since 2 + 1 + 2 + 0 + 7 + 239 + 415 = 666.

It is not a de Polignac number, because 21207239415 - 2¹ = 21207239413 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21207239415.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21207239411) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 235635949 + ... + 235636038.

It is an arithmetic number, because the mean of its divisors is an integer number (3063267922).

Almost surely, 2^21207239415 is an apocalyptic number.

21207239415 is a deficient number, since it is larger than the sum of its proper divisors (15551975649).

21207239415 is a wasteful number, since it uses less digits than its factorization.

21207239415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 471271998 (or 471271995 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The spelling of 21207239415 in words is "twenty-one billion, two hundred seven million, two hundred thirty-nine thousand, four hundred fifteen".