31220402 has 4 divisors (see below), whose sum is σ = 46830606. Its totient is φ = 15610200.

The previous prime is 31220383. The next prime is 31220419. The reversal of 31220402 is 20402213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 20402213 = 13 ⋅1569401.

It can be written as a sum of positive squares in only one way, i.e., 27867841 + 3352561 = 5279^2 + 1831^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7805099 + ... + 7805102.

Almost surely, 2^31220402 is an apocalyptic number.

31220402 is a deficient number, since it is larger than the sum of its proper divisors (15610204).

31220402 is a wasteful number, since it uses less digits than its factorization.

31220402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15610203.

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 31220402 is about 5587.5219910082. The cubic root of 31220402 is about 314.8807880132.

Adding to 31220402 its reverse (20402213), we get a palindrome (51622615).

The spelling of 31220402 in words is "thirty-one million, two hundred twenty thousand, four hundred two".