31389072 has 160 divisors (see below), whose sum is σ = 101243520. Its totient is φ = 8232960.

The previous prime is 31389053. The next prime is 31389079. The reversal of 31389072 is 27098313.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (31389079) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 116554 + ... + 116822.

It is an arithmetic number, because the mean of its divisors is an integer number (632772).

Almost surely, 2^31389072 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31389072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50621760).

31389072 is an abundant number, since it is smaller than the sum of its proper divisors (69854448).

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

31389072 is a wasteful number, since it uses less digits than its factorization.

31389072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321 (or 315 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 31389072 is about 5602.5951129811. The cubic root of 31389072 is about 315.4468236843.

The spelling of 31389072 in words is "thirty-one million, three hundred eighty-nine thousand, seventy-two".