31220641 has 2 divisors, whose sum is σ = 31220642. Its totient is φ = 31220640.

The previous prime is 31220633. The next prime is 31220659. The reversal of 31220641 is 14602213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28398241 + 2822400 = 5329^2 + 1680^2 .

It is a cyclic number.

It is not a de Polignac number, because 31220641 - 2³ = 31220633 is a prime.

It is not a weakly prime, because it can be changed into another prime (31220621) by changing a digit.

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, 15610320 + 15610321.

It is an arithmetic number, because the mean of its divisors is an integer number (15610321).

Almost surely, 2^31220641 is an apocalyptic number.

It is an amenable number.

31220641 is a deficient number, since it is larger than the sum of its proper divisors (1).

31220641 is an equidigital number, since it uses as much as digits as its factorization.

31220641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 31220641 is about 5587.5433779077. The cubic root of 31220641 is about 314.8815915083.

Adding to 31220641 its reverse (14602213), we get a palindrome (45822854).

The spelling of 31220641 in words is "thirty-one million, two hundred twenty thousand, six hundred forty-one".