31420409 has 2 divisors, whose sum is σ = 31420410. Its totient is φ = 31420408.

The previous prime is 31420381. The next prime is 31420447. The reversal of 31420409 is 90402413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19669225 + 11751184 = 4435^2 + 3428^2 .

It is a cyclic number.

It is not a de Polignac number, because 31420409 - 2⁸ = 31420153 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (31420469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15710204 + 15710205.

It is an arithmetic number, because the mean of its divisors is an integer number (15710205).

Almost surely, 2^31420409 is an apocalyptic number.

It is an amenable number.

31420409 is a deficient number, since it is larger than the sum of its proper divisors (1).

31420409 is an equidigital number, since it uses as much as digits as its factorization.

31420409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 31420409 is about 5605.3910657509. The cubic root of 31420409 is about 315.5517632776.

The spelling of 31420409 in words is "thirty-one million, four hundred twenty thousand, four hundred nine".