39640457 has 2 divisors, whose sum is σ = 39640458. Its totient is φ = 39640456.

The previous prime is 39640439. The next prime is 39640487. The reversal of 39640457 is 75404693.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39639616 + 841 = 6296^2 + 29^2 .

It is a cyclic number.

It is not a de Polignac number, because 39640457 - 2²⁴ = 22863241 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 39640457.

It is not a weakly prime, because it can be changed into another prime (39640417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19820228 + 19820229.

It is an arithmetic number, because the mean of its divisors is an integer number (19820229).

Almost surely, 2^39640457 is an apocalyptic number.

It is an amenable number.

39640457 is a deficient number, since it is larger than the sum of its proper divisors (1).

39640457 is an equidigital number, since it uses as much as digits as its factorization.

39640457 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 38.

The square root of 39640457 is about 6296.0667880829. The cubic root of 39640457 is about 340.9674206282.

The spelling of 39640457 in words is "thirty-nine million, six hundred forty thousand, four hundred fifty-seven".