399149551 has 2 divisors, whose sum is σ = 399149552. Its totient is φ = 399149550.

The previous prime is 399149507. The next prime is 399149563. The reversal of 399149551 is 155941993.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (155941993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 399149551 - 2⁹ = 399149039 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399149501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199574775 + 199574776.

It is an arithmetic number, because the mean of its divisors is an integer number (199574776).

Almost surely, 2^399149551 is an apocalyptic number.

399149551 is a deficient number, since it is larger than the sum of its proper divisors (1).

399149551 is an equidigital number, since it uses as much as digits as its factorization.

399149551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 218700, while the sum is 46.

The square root of 399149551 is about 19978.7274619782. The cubic root of 399149551 is about 736.2837490667.

The spelling of 399149551 in words is "three hundred ninety-nine million, one hundred forty-nine thousand, five hundred fifty-one".