21520544502 has 16 divisors (see below), whose sum is σ = 43080553152. Its totient is φ = 7166937480.

The previous prime is 21520544459. The next prime is 21520544537. The reversal of 21520544502 is 20544502512.

It is a self number, because there is not a number n which added to its sum of digits gives 21520544502.

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, 1637248 + ... + 1650339.

It is an arithmetic number, because the mean of its divisors is an integer number (2692534572).

Almost surely, 2^21520544502 is an apocalyptic number.

21520544502 is an abundant number, since it is smaller than the sum of its proper divisors (21560008650).

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

21520544502 is a wasteful number, since it uses less digits than its factorization.

21520544502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3288683.

The product of its (nonzero) digits is 16000, while the sum is 30.

The spelling of 21520544502 in words is "twenty-one billion, five hundred twenty million, five hundred forty-four thousand, five hundred two".