31378689 has 6 divisors (see below), whose sum is σ = 45324786. Its totient is φ = 20919120.

The previous prime is 31378673. The next prime is 31378717. The reversal of 31378689 is 98687313.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 27217089 + 4161600 = 5217^2 + 2040^2 .

It is not a de Polignac number, because 31378689 - 2⁴ = 31378673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31378639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1743252 + ... + 1743269.

It is an arithmetic number, because the mean of its divisors is an integer number (7554131).

Almost surely, 2^31378689 is an apocalyptic number.

It is an amenable number.

31378689 is a deficient number, since it is larger than the sum of its proper divisors (13946097).

31378689 is a wasteful number, since it uses less digits than its factorization.

31378689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3486527 (or 3486524 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 31378689 is about 5601.6684121786. The cubic root of 31378689 is about 315.4120382705.

The spelling of 31378689 in words is "thirty-one million, three hundred seventy-eight thousand, six hundred eighty-nine".