31221342 has 32 divisors (see below), whose sum is σ = 71776800. Its totient is φ = 10047744.

The previous prime is 31221329. The next prime is 31221343. The reversal of 31221342 is 24312213.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31221343) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8403 + ... + 11534.

It is an arithmetic number, because the mean of its divisors is an integer number (2243025).

Almost surely, 2^31221342 is an apocalyptic number.

31221342 is an abundant number, since it is smaller than the sum of its proper divisors (40555458).

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

31221342 is a wasteful number, since it uses less digits than its factorization.

31221342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19977 (or 19971 counting only the distinct ones).

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

The square root of 31221342 is about 5587.6061063751. The cubic root of 31221342 is about 314.8839481793.

Adding to 31221342 its reverse (24312213), we get a palindrome (55533555).

The spelling of 31221342 in words is "thirty-one million, two hundred twenty-one thousand, three hundred forty-two".