31289472 has 96 divisors (see below), whose sum is σ = 91135980. Its totient is φ = 10303488.

The previous prime is 31289449. The next prime is 31289477. The reversal of 31289472 is 27498213.

It can be written as a sum of positive squares in 2 ways, for example, as 30735936 + 553536 = 5544^2 + 744^2 .

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (31289477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 180778 + ... + 180950.

Almost surely, 2^31289472 is an apocalyptic number.

31289472 is a gapful number since it is divisible by the number (32) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31289472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45567990).

31289472 is an abundant number, since it is smaller than the sum of its proper divisors (59846508).

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

31289472 is a wasteful number, since it uses less digits than its factorization.

31289472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350 (or 335 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 31289472 is about 5593.6993126195. The cubic root of 31289472 is about 315.1128242861.

The spelling of 31289472 in words is "thirty-one million, two hundred eighty-nine thousand, four hundred seventy-two".