312729861 has 4 divisors (see below), whose sum is σ = 416973152. Its totient is φ = 208486572.

The previous prime is 312729853. The next prime is 312729871. The reversal of 312729861 is 168927213.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 312729861 - 2³ = 312729853 is a prime.

It is a super-2 number, since 2×312729861² = 195599931922158642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312729821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52121641 + ... + 52121646.

It is an arithmetic number, because the mean of its divisors is an integer number (104243288).

Almost surely, 2^312729861 is an apocalyptic number.

It is an amenable number.

312729861 is a deficient number, since it is larger than the sum of its proper divisors (104243291).

312729861 is a wasteful number, since it uses less digits than its factorization.

312729861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104243290.

The product of its digits is 36288, while the sum is 39.

The square root of 312729861 is about 17684.1697854324. The cubic root of 312729861 is about 678.7707470367.

The spelling of 312729861 in words is "three hundred twelve million, seven hundred twenty-nine thousand, eight hundred sixty-one".