31118642 has 4 divisors (see below), whose sum is σ = 46677966. Its totient is φ = 15559320.

The previous prime is 31118641. The next prime is 31118663. The reversal of 31118642 is 24681113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24681113 = 719 ⋅34327.

It can be written as a sum of positive squares in only one way, i.e., 17048641 + 14070001 = 4129^2 + 3751^2 .

It is not an unprimeable number, because it can be changed into a prime (31118641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7779659 + ... + 7779662.

Almost surely, 2^31118642 is an apocalyptic number.

31118642 is a deficient number, since it is larger than the sum of its proper divisors (15559324).

31118642 is a wasteful number, since it uses less digits than its factorization.

31118642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15559323.

The product of its digits is 1152, while the sum is 26.

The square root of 31118642 is about 5578.4085544176. The cubic root of 31118642 is about 314.5383074231.

Adding to 31118642 its reverse (24681113), we get a palindrome (55799755).

The spelling of 31118642 in words is "thirty-one million, one hundred eighteen thousand, six hundred forty-two".