21790454990 has 16 divisors (see below), whose sum is σ = 41530043952. Its totient is φ = 8203465344.

The previous prime is 21790454977. The next prime is 21790455017. The reversal of 21790454990 is 9945409712.

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, 64089404 + ... + 64089743.

It is an arithmetic number, because the mean of its divisors is an integer number (2595627747).

Almost surely, 2^21790454990 is an apocalyptic number.

21790454990 is a deficient number, since it is larger than the sum of its proper divisors (19739588962).

21790454990 is a wasteful number, since it uses less digits than its factorization.

21790454990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128179171.

The product of its (nonzero) digits is 816480, while the sum is 50.

The spelling of 21790454990 in words is "twenty-one billion, seven hundred ninety million, four hundred fifty-four thousand, nine hundred ninety".