864215251 has 2 divisors, whose sum is σ = 864215252. Its totient is φ = 864215250.

The previous prime is 864215239. The next prime is 864215279. The reversal of 864215251 is 152512468.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 864215251 - 2⁷ = 864215123 is a prime.

It is not a weakly prime, because it can be changed into another prime (864215221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432107625 + 432107626.

It is an arithmetic number, because the mean of its divisors is an integer number (432107626).

Almost surely, 2^864215251 is an apocalyptic number.

864215251 is a deficient number, since it is larger than the sum of its proper divisors (1).

864215251 is an equidigital number, since it uses as much as digits as its factorization.

864215251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19200, while the sum is 34.

The square root of 864215251 is about 29397.5381792422. The cubic root of 864215251 is about 952.5197194430.

The spelling of 864215251 in words is "eight hundred sixty-four million, two hundred fifteen thousand, two hundred fifty-one".