31909161387 has 4 divisors (see below), whose sum is σ = 42545548520. Its totient is φ = 21272774256.

The previous prime is 31909161373. The next prime is 31909161409. The reversal of 31909161387 is 78316190913.

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

It is not a de Polignac number, because 31909161387 - 2⁷ = 31909161259 is a prime.

It is a super-2 number, since 2×31909161387² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31909161587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5318193562 + ... + 5318193567.

It is an arithmetic number, because the mean of its divisors is an integer number (10636387130).

Almost surely, 2^31909161387 is an apocalyptic number.

31909161387 is a deficient number, since it is larger than the sum of its proper divisors (10636387133).

31909161387 is a wasteful number, since it uses less digits than its factorization.

31909161387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10636387132.

The product of its (nonzero) digits is 244944, while the sum is 48.

The spelling of 31909161387 in words is "thirty-one billion, nine hundred nine million, one hundred sixty-one thousand, three hundred eighty-seven".