867856993 has 2 divisors, whose sum is σ = 867856994. Its totient is φ = 867856992.

The previous prime is 867856973. The next prime is 867857009. The reversal of 867856993 is 399658768.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 651678784 + 216178209 = 25528^2 + 14703^2 .

It is a cyclic number.

It is not a de Polignac number, because 867856993 - 2²¹ = 865759841 is a prime.

It is not a weakly prime, because it can be changed into another prime (867856903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433928496 + 433928497.

It is an arithmetic number, because the mean of its divisors is an integer number (433928497).

Almost surely, 2^867856993 is an apocalyptic number.

It is an amenable number.

867856993 is a deficient number, since it is larger than the sum of its proper divisors (1).

867856993 is an equidigital number, since it uses as much as digits as its factorization.

867856993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19595520, while the sum is 61.

The square root of 867856993 is about 29459.4126384081. The cubic root of 867856993 is about 953.8557947512.

The spelling of 867856993 in words is "eight hundred sixty-seven million, eight hundred fifty-six thousand, nine hundred ninety-three".