21690183998 has 16 divisors (see below), whose sum is σ = 38090080224. Its totient is φ = 9069066240.

The previous prime is 21690183959. The next prime is 21690184001. The reversal of 21690183998 is 89938109612.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18893315 + ... + 18894462.

It is an arithmetic number, because the mean of its divisors is an integer number (2380630014).

Almost surely, 2^21690183998 is an apocalyptic number.

21690183998 is a deficient number, since it is larger than the sum of its proper divisors (16399896226).

21690183998 is a wasteful number, since it uses less digits than its factorization.

21690183998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37787827.

The product of its (nonzero) digits is 1679616, while the sum is 56.

The spelling of 21690183998 in words is "twenty-one billion, six hundred ninety million, one hundred eighty-three thousand, nine hundred ninety-eight".