31243212 has 288 divisors, whose sum is σ = 115530240. Its totient is φ = 7050240.

The previous prime is 31243211. The next prime is 31243213. The reversal of 31243212 is 21234213.

It is an interprime number because it is at equal distance from previous prime (31243211) and next prime (31243213).

It is a super-2 number, since 2×31243212² = 1952276592153888, which contains 22 as substring.

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 congruent number.

It is not an unprimeable number, because it can be changed into a prime (31243211) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1837828 + ... + 1837844.

Almost surely, 2^31243212 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 31243212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (57765120).

31243212 is an abundant number, since it is smaller than the sum of its proper divisors (84287028).

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

31243212 is a wasteful number, since it uses less digits than its factorization.

31243212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78 (or 53 counting only the distinct ones).

The product of its digits is 288, while the sum is 18.

The square root of 31243212 is about 5589.5627735987. The cubic root of 31243212 is about 314.9574545713.

Adding to 31243212 its reverse (21234213), we get a palindrome (52477425).

It can be divided in two parts, 3124 and 3212, that added together give a palindrome (6336).

The spelling of 31243212 in words is "thirty-one million, two hundred forty-three thousand, two hundred twelve".