861764857 has 2 divisors, whose sum is σ = 861764858. Its totient is φ = 861764856.

The previous prime is 861764837. The next prime is 861764951. The reversal of 861764857 is 758467168.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 818875456 + 42889401 = 28616^2 + 6549^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-861764857 is a prime.

It is not a weakly prime, because it can be changed into another prime (861764807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430882428 + 430882429.

It is an arithmetic number, because the mean of its divisors is an integer number (430882429).

Almost surely, 2^861764857 is an apocalyptic number.

It is an amenable number.

861764857 is a deficient number, since it is larger than the sum of its proper divisors (1).

861764857 is an equidigital number, since it uses as much as digits as its factorization.

861764857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2257920, while the sum is 52.

The square root of 861764857 is about 29355.8317374930. The cubic root of 861764857 is about 951.6186098064.

The spelling of 861764857 in words is "eight hundred sixty-one million, seven hundred sixty-four thousand, eight hundred fifty-seven".