21990732558 has 16 divisors (see below), whose sum is σ = 43983889920. Its totient is φ = 7329840056.

The previous prime is 21990732529. The next prime is 21990732559. The reversal of 21990732558 is 85523709912.

It is a self number, because there is not a number n which added to its sum of digits gives 21990732558.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21990732559) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29923 + ... + 211841.

It is an arithmetic number, because the mean of its divisors is an integer number (2748993120).

Almost surely, 2^21990732558 is an apocalyptic number.

21990732558 is an abundant number, since it is smaller than the sum of its proper divisors (21993157362).

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

21990732558 is a wasteful number, since it uses less digits than its factorization.

21990732558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202071.

The product of its (nonzero) digits is 1360800, while the sum is 51.

The spelling of 21990732558 in words is "twenty-one billion, nine hundred ninety million, seven hundred thirty-two thousand, five hundred fifty-eight".