21385376990 has 16 divisors (see below), whose sum is σ = 38557738800. Its totient is φ = 8539915200.

The previous prime is 21385376959. The next prime is 21385377017. The reversal of 21385376990 is 9967358312.

It is a Curzon number.

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, 1773140 + ... + 1785159.

It is an arithmetic number, because the mean of its divisors is an integer number (2409858675).

Almost surely, 2^21385376990 is an apocalyptic number.

21385376990 is a deficient number, since it is larger than the sum of its proper divisors (17172361810).

21385376990 is a wasteful number, since it uses less digits than its factorization.

21385376990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3558907.

The product of its (nonzero) digits is 2449440, while the sum is 53.

The spelling of 21385376990 in words is "twenty-one billion, three hundred eighty-five million, three hundred seventy-six thousand, nine hundred ninety".