861997311 has 12 divisors (see below), whose sum is σ = 1422979792. Its totient is φ = 492569856.

The previous prime is 861997273. The next prime is 861997313. The reversal of 861997311 is 113799168.

It is not a de Polignac number, because 861997311 - 2⁷ = 861997183 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861997313) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6841186 + ... + 6841311.

Almost surely, 2^861997311 is an apocalyptic number.

861997311 is a deficient number, since it is larger than the sum of its proper divisors (560982481).

861997311 is a wasteful number, since it uses less digits than its factorization.

861997311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13682510 (or 13682507 counting only the distinct ones).

The product of its digits is 81648, while the sum is 45.

The square root of 861997311 is about 29359.7907179190. The cubic root of 861997311 is about 951.7041658851.

The spelling of 861997311 in words is "eight hundred sixty-one million, nine hundred ninety-seven thousand, three hundred eleven".