31315242 has 16 divisors (see below), whose sum is σ = 71577792. Its totient is φ = 8947200.

The previous prime is 31315231. The next prime is 31315247. The reversal of 31315242 is 24251313.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (31315247) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 372759 + ... + 372842.

It is an arithmetic number, because the mean of its divisors is an integer number (4473612).

Almost surely, 2^31315242 is an apocalyptic number.

31315242 is an abundant number, since it is smaller than the sum of its proper divisors (40262550).

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

31315242 is a wasteful number, since it uses less digits than its factorization.

31315242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 745613.

The product of its digits is 720, while the sum is 21.

The square root of 31315242 is about 5596.0023230874. The cubic root of 31315242 is about 315.1993094907.

Adding to 31315242 its reverse (24251313), we get a palindrome (55566555).

The spelling of 31315242 in words is "thirty-one million, three hundred fifteen thousand, two hundred forty-two".