31478139 has 80 divisors (see below), whose sum is σ = 60403200. Its totient is φ = 16193520.

The previous prime is 31478129. The next prime is 31478147. The reversal of 31478139 is 93187413.

It is a happy number.

It is not a de Polignac number, because 31478139 - 2⁸ = 31477883 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31478129) 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 79 ways as a sum of consecutive naturals, for example, 305562 + ... + 305664.

It is an arithmetic number, because the mean of its divisors is an integer number (755040).

Almost surely, 2^31478139 is an apocalyptic number.

31478139 is a deficient number, since it is larger than the sum of its proper divisors (28925061).

31478139 is a wasteful number, since it uses less digits than its factorization.

31478139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147 (or 124 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 31478139 is about 5610.5382094769. The cubic root of 31478139 is about 315.7449037493.

The spelling of 31478139 in words is "thirty-one million, four hundred seventy-eight thousand, one hundred thirty-nine".