399925693 has 2 divisors, whose sum is σ = 399925694. Its totient is φ = 399925692.

The previous prime is 399925681. The next prime is 399925703. The reversal of 399925693 is 396529993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 308283364 + 91642329 = 17558^2 + 9573^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399925693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399925993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199962846 + 199962847.

It is an arithmetic number, because the mean of its divisors is an integer number (199962847).

Almost surely, 2^399925693 is an apocalyptic number.

It is an amenable number.

399925693 is a deficient number, since it is larger than the sum of its proper divisors (1).

399925693 is an equidigital number, since it uses as much as digits as its factorization.

399925693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3542940, while the sum is 55.

The square root of 399925693 is about 19998.1422387181. The cubic root of 399925693 is about 736.7606720145.

It can be divided in two parts, 3999 and 25693, that added together give a palindrome (29692).

The spelling of 399925693 in words is "three hundred ninety-nine million, nine hundred twenty-five thousand, six hundred ninety-three".