19978901692 has 24 divisors (see below), whose sum is σ = 35914404960. Its totient is φ = 9717739200.

The previous prime is 19978901681. The next prime is 19978901699. The reversal of 19978901692 is 29610987991.

It is a self number, because there is not a number n which added to its sum of digits gives 19978901692.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19978901699) by changing a digit.

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, 1328817 + ... + 1343767.

It is an arithmetic number, because the mean of its divisors is an integer number (1496433540).

Almost surely, 2^19978901692 is an apocalyptic number.

It is an amenable number.

19978901692 is a deficient number, since it is larger than the sum of its proper divisors (15935503268).

19978901692 is a wasteful number, since it uses less digits than its factorization.

19978901692 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24021 (or 24019 counting only the distinct ones).

The product of its (nonzero) digits is 4408992, while the sum is 61.

The spelling of 19978901692 in words is "nineteen billion, nine hundred seventy-eight million, nine hundred one thousand, six hundred ninety-two".