21261598484 has 24 divisors (see below), whose sum is σ = 43243932480. Its totient is φ = 8957670336.

The previous prime is 21261598459. The next prime is 21261598499. The reversal of 21261598484 is 48489516212.

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, 6433457 + ... + 6436760.

It is an arithmetic number, because the mean of its divisors is an integer number (1801830520).

Almost surely, 2^21261598484 is an apocalyptic number.

It is an amenable number.

21261598484 is an abundant number, since it is smaller than the sum of its proper divisors (21982333996).

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

21261598484 is a wasteful number, since it uses less digits than its factorization.

21261598484 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12870287 (or 12870285 counting only the distinct ones).

The product of its digits is 1105920, while the sum is 50.

The spelling of 21261598484 in words is "twenty-one billion, two hundred sixty-one million, five hundred ninety-eight thousand, four hundred eighty-four".