1897920636 has 12 divisors (see below), whose sum is σ = 4428481512. Its totient is φ = 632640208.

The previous prime is 1897920611. The next prime is 1897920641. The reversal of 1897920636 is 6360297981.

It is a tau number, because it is divible by the number of its divisors (12).

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 3 ways as a sum of consecutive naturals, for example, 79080015 + ... + 79080038.

It is an arithmetic number, because the mean of its divisors is an integer number (369040126).

Almost surely, 2^1897920636 is an apocalyptic number.

It is an amenable number.

1897920636 is an abundant number, since it is smaller than the sum of its proper divisors (2530560876).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1897920636 is a wasteful number, since it uses less digits than its factorization.

1897920636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158160060 (or 158160058 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 51.

The square root of 1897920636 is about 43565.1309650275. The cubic root of 1897920636 is about 1238.1103362955.

The spelling of 1897920636 in words is "one billion, eight hundred ninety-seven million, nine hundred twenty thousand, six hundred thirty-six".