399172547 has 2 divisors, whose sum is σ = 399172548. Its totient is φ = 399172546.

The previous prime is 399172537. The next prime is 399172607. The reversal of 399172547 is 745271993.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 399172547 - 2⁴ = 399172531 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (399172507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199586273 + 199586274.

It is an arithmetic number, because the mean of its divisors is an integer number (199586274).

Almost surely, 2^399172547 is an apocalyptic number.

399172547 is a deficient number, since it is larger than the sum of its proper divisors (1).

399172547 is an equidigital number, since it uses as much as digits as its factorization.

399172547 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 476280, while the sum is 47.

The square root of 399172547 is about 19979.3029658194. The cubic root of 399172547 is about 736.2978885088.

The spelling of 399172547 in words is "three hundred ninety-nine million, one hundred seventy-two thousand, five hundred forty-seven".