19721764252 has 12 divisors (see below), whose sum is σ = 34514858056. Its totient is φ = 9860376240.

The previous prime is 19721764219. The next prime is 19721764261. The reversal of 19721764252 is 25246712791.

It is a super-2 number, since 2×19721764252² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30699 + ... + 200962.

Almost surely, 2^19721764252 is an apocalyptic number.

It is an amenable number.

19721764252 is a deficient number, since it is larger than the sum of its proper divisors (14793093804).

19721764252 is a wasteful number, since it uses less digits than its factorization.

19721764252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252948 (or 252946 counting only the distinct ones).

The product of its digits is 423360, while the sum is 46.

The spelling of 19721764252 in words is "nineteen billion, seven hundred twenty-one million, seven hundred sixty-four thousand, two hundred fifty-two".