31400442 has 12 divisors (see below), whose sum is σ = 68034330. Its totient is φ = 10466808.

The previous prime is 31400441. The next prime is 31400459. The reversal of 31400442 is 24400413.

It can be written as a sum of positive squares in only one way, i.e., 31371201 + 29241 = 5601^2 + 171^2 .

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 1744469 = 31400442 / (3 + 1 + 4 + 0 + 0 + 4 + 4 + 2).

It is not an unprimeable number, because it can be changed into a prime (31400441) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 872217 + ... + 872252.

Almost surely, 2^31400442 is an apocalyptic number.

31400442 is an abundant number, since it is smaller than the sum of its proper divisors (36633888).

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

31400442 is a wasteful number, since it uses less digits than its factorization.

31400442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1744477 (or 1744474 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 31400442 is about 5603.6097294512. The cubic root of 31400442 is about 315.4849069745.

Adding to 31400442 its reverse (24400413), we get a palindrome (55800855).

The spelling of 31400442 in words is "thirty-one million, four hundred thousand, four hundred forty-two".