861157243 has 2 divisors, whose sum is σ = 861157244. Its totient is φ = 861157242.

The previous prime is 861157207. The next prime is 861157247. The reversal of 861157243 is 342751168.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 861157243 - 2²⁹ = 324286331 is a prime.

It is a super-2 number, since 2×861157243² = 1483183594342722098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (861157247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430578621 + 430578622.

It is an arithmetic number, because the mean of its divisors is an integer number (430578622).

Almost surely, 2^861157243 is an apocalyptic number.

861157243 is a deficient number, since it is larger than the sum of its proper divisors (1).

861157243 is an equidigital number, since it uses as much as digits as its factorization.

861157243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 37.

The square root of 861157243 is about 29345.4807934714. The cubic root of 861157243 is about 951.3949011636.

The spelling of 861157243 in words is "eight hundred sixty-one million, one hundred fifty-seven thousand, two hundred forty-three".