31222140 has 24 divisors (see below), whose sum is σ = 87422160. Its totient is φ = 8325888.

The previous prime is 31222133. The next prime is 31222157. The reversal of 31222140 is 4122213.

31222140 is nontrivially palindromic in base 9.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 260125 + ... + 260244.

It is an arithmetic number, because the mean of its divisors is an integer number (3642590).

Almost surely, 2^31222140 is an apocalyptic number.

31222140 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31222140 is an abundant number, since it is smaller than the sum of its proper divisors (56200020).

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

31222140 is a wasteful number, since it uses less digits than its factorization.

31222140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520381 (or 520379 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 31222140 is about 5587.6775139587. The cubic root of 31222140 is about 314.8866309089.

Adding to 31222140 its reverse (4122213), we get a palindrome (35344353).

The spelling of 31222140 in words is "thirty-one million, two hundred twenty-two thousand, one hundred forty".