31389930 has 160 divisors (see below), whose sum is σ = 99525888. Its totient is φ = 6998400.

The previous prime is 31389923. The next prime is 31389961. The reversal of 31389930 is 3998313.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 115695 + ... + 115965.

Almost surely, 2^31389930 is an apocalyptic number.

31389930 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 31389930, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49762944).

31389930 is an abundant number, since it is smaller than the sum of its proper divisors (68135958).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31389930 is a wasteful number, since it uses less digits than its factorization.

31389930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314 (or 305 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 31389930 is about 5602.6716841164. The cubic root of 31389930 is about 315.4496978364.

The spelling of 31389930 in words is "thirty-one million, three hundred eighty-nine thousand, nine hundred thirty".