21990232555518 has 8 divisors (see below), whose sum is σ = 43980465111048. Its totient is φ = 7330077518504.

The previous prime is 21990232555451. The next prime is 21990232555549. The reversal of 21990232555518 is 81555523209912.

It is a sphenic number, since it is the product of 3 distinct primes.

21990232555518 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1832519379621 + ... + 1832519379632.

It is an arithmetic number, because the mean of its divisors is an integer number (5497558138881).

Almost surely, 2^{21990232555518} is an apocalyptic number.

21990232555518 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21990232555518 is a wasteful number, since it uses less digits than its factorization.

21990232555518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3665038759258.

The product of its (nonzero) digits is 9720000, while the sum is 57.

The spelling of 21990232555518 in words is "twenty-one trillion, nine hundred ninety billion, two hundred thirty-two million, five hundred fifty-five thousand, five hundred eighteen".