199917721924 has 12 divisors (see below), whose sum is σ = 349860963004. Its totient is φ = 99957446784.

The previous prime is 199917721919. The next prime is 199917721943. The reversal of 199917721924 is 429127719991.

It can be written as a sum of positive squares in 2 ways, for example, as 189790922500 + 10126799424 = 435650^2 + 100632^2 .

It is a hoax number, since the sum of its digits (61) coincides with the sum of the digits of its distinct prime factors.

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, 4912 + ... + 632344.

Almost surely, 2^199917721924 is an apocalyptic number.

It is an amenable number.

199917721924 is a deficient number, since it is larger than the sum of its proper divisors (149943241080).

199917721924 is a wasteful number, since it uses less digits than its factorization.

199917721924 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 707094 (or 707092 counting only the distinct ones).

The product of its digits is 5143824, while the sum is 61.

The spelling of 199917721924 in words is "one hundred ninety-nine billion, nine hundred seventeen million, seven hundred twenty-one thousand, nine hundred twenty-four".