31220402189 has 2 divisors, whose sum is σ = 31220402190. Its totient is φ = 31220402188.

The previous prime is 31220402183. The next prime is 31220402231. The reversal of 31220402189 is 98120402213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28676712964 + 2543689225 = 169342^2 + 50435^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31220402189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31220402183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15610201094 + 15610201095.

It is an arithmetic number, because the mean of its divisors is an integer number (15610201095).

Almost surely, 2^31220402189 is an apocalyptic number.

It is an amenable number.

31220402189 is a deficient number, since it is larger than the sum of its proper divisors (1).

31220402189 is an equidigital number, since it uses as much as digits as its factorization.

31220402189 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 32.

The spelling of 31220402189 in words is "thirty-one billion, two hundred twenty million, four hundred two thousand, one hundred eighty-nine".