820193957 has 16 divisors (see below), whose sum is σ = 946017600. Its totient is φ = 703261440.

The previous prime is 820193923. The next prime is 820193963. The reversal of 820193957 is 759391028.

It is not a de Polignac number, because 820193957 - 2²⁰ = 819145381 is a prime.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820193977) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39293 + ... + 56429.

It is an arithmetic number, because the mean of its divisors is an integer number (59126100).

Almost surely, 2^820193957 is an apocalyptic number.

It is an amenable number.

820193957 is a deficient number, since it is larger than the sum of its proper divisors (125823643).

820193957 is a wasteful number, since it uses less digits than its factorization.

820193957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17396.

The product of its (nonzero) digits is 136080, while the sum is 44.

The square root of 820193957 is about 28639.0285624356. The cubic root of 820193957 is about 936.0639539939.

The spelling of 820193957 in words is "eight hundred twenty million, one hundred ninety-three thousand, nine hundred fifty-seven".