31331402 has 4 divisors (see below), whose sum is σ = 46997106. Its totient is φ = 15665700.

The previous prime is 31331393. The next prime is 31331407. The reversal of 31331402 is 20413313.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 20413313 = 1951 ⋅10463.

It can be written as a sum of positive squares in only one way, i.e., 19018321 + 12313081 = 4361^2 + 3509^2 .

It is not an unprimeable number, because it can be changed into a prime (31331407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7832849 + ... + 7832852.

Almost surely, 2^31331402 is an apocalyptic number.

31331402 is a deficient number, since it is larger than the sum of its proper divisors (15665704).

31331402 is a wasteful number, since it uses less digits than its factorization.

31331402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15665703.

The product of its (nonzero) digits is 216, while the sum is 17.

The square root of 31331402 is about 5597.4460247509. The cubic root of 31331402 is about 315.2535189277.

Adding to 31331402 its reverse (20413313), we get a palindrome (51744715).

The spelling of 31331402 in words is "thirty-one million, three hundred thirty-one thousand, four hundred two".