31213332 has 18 divisors (see below), whose sum is σ = 78900458. Its totient is φ = 10404432.

The previous prime is 31213321. The next prime is 31213363. The reversal of 31213332 is 23331213.

It can be written as a sum of positive squares in only one way, i.e., 25765776 + 5447556 = 5076^2 + 2334^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

It is a nialpdrome in base 12.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 433483 + ... + 433554.

Almost surely, 2^31213332 is an apocalyptic number.

It is an amenable number.

31213332 is an abundant number, since it is smaller than the sum of its proper divisors (47687126).

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

31213332 is a wasteful number, since it uses less digits than its factorization.

31213332 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 867047 (or 867042 counting only the distinct ones).

The product of its digits is 324, while the sum is 18.

The square root of 31213332 is about 5586.8892954846. The cubic root of 31213332 is about 314.8570174968.

Adding to 31213332 its reverse (23331213), we get a palindrome (54544545).

The spelling of 31213332 in words is "thirty-one million, two hundred thirteen thousand, three hundred thirty-two".