399440651 has 2 divisors, whose sum is σ = 399440652. Its totient is φ = 399440650.

The previous prime is 399440579. The next prime is 399440681. The reversal of 399440651 is 156044993.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 399440651 - 2²² = 395246347 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 399440599 and 399440608.

It is not a weakly prime, because it can be changed into another prime (399440681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199720325 + 199720326.

It is an arithmetic number, because the mean of its divisors is an integer number (199720326).

Almost surely, 2^399440651 is an apocalyptic number.

399440651 is a deficient number, since it is larger than the sum of its proper divisors (1).

399440651 is an equidigital number, since it uses as much as digits as its factorization.

399440651 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116640, while the sum is 41.

The square root of 399440651 is about 19986.0113829648. The cubic root of 399440651 is about 736.4626962940.

The spelling of 399440651 in words is "three hundred ninety-nine million, four hundred forty thousand, six hundred fifty-one".