820140657 has 16 divisors (see below), whose sum is σ = 1251655680. Its totient is φ = 467932752.

The previous prime is 820140653. The next prime is 820140691. The reversal of 820140657 is 756041028.

It is not a de Polignac number, because 820140657 - 2² = 820140653 is a prime.

It is not an unprimeable number, because it can be changed into a prime (820140653) 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, 15793 + ... + 43470.

It is an arithmetic number, because the mean of its divisors is an integer number (78228480).

Almost surely, 2^820140657 is an apocalyptic number.

It is an amenable number.

820140657 is a deficient number, since it is larger than the sum of its proper divisors (431515023).

820140657 is a wasteful number, since it uses less digits than its factorization.

820140657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59932.

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 820140657 is about 28638.0979989943. The cubic root of 820140657 is about 936.0436769651.

The spelling of 820140657 in words is "eight hundred twenty million, one hundred forty thousand, six hundred fifty-seven".