31906786154 has 4 divisors (see below), whose sum is σ = 47860179234. Its totient is φ = 15953393076.

The previous prime is 31906786139. The next prime is 31906786159. The reversal of 31906786154 is 45168760913.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 17457544129 + 14449242025 = 132127^2 + 120205^2 .

It is a super-2 number, since 2×31906786154² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31906786159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7976696537 + ... + 7976696540.

Almost surely, 2^31906786154 is an apocalyptic number.

31906786154 is a deficient number, since it is larger than the sum of its proper divisors (15953393080).

31906786154 is a wasteful number, since it uses less digits than its factorization.

31906786154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15953393079.

The product of its (nonzero) digits is 1088640, while the sum is 50.

The spelling of 31906786154 in words is "thirty-one billion, nine hundred six million, seven hundred eighty-six thousand, one hundred fifty-four".