31405442 has 16 divisors (see below), whose sum is σ = 51744960. Its totient is φ = 14229072.

The previous prime is 31405441. The next prime is 31405453. The reversal of 31405442 is 24450413.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is not an unprimeable number, because it can be changed into a prime (31405441) 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, 17093 + ... + 18840.

It is an arithmetic number, because the mean of its divisors is an integer number (3234060).

Almost surely, 2^31405442 is an apocalyptic number.

31405442 is a deficient number, since it is larger than the sum of its proper divisors (20339518).

31405442 is a wasteful number, since it uses less digits than its factorization.

31405442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35977.

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 31405442 is about 5604.0558526838. The cubic root of 31405442 is about 315.5016513334.

Adding to 31405442 its reverse (24450413), we get a palindrome (55855855).

The spelling of 31405442 in words is "thirty-one million, four hundred five thousand, four hundred forty-two".