398157669 has 72 divisors (see below), whose sum is σ = 740754560. Its totient is φ = 200667456.

The previous prime is 398157659. The next prime is 398157671. The reversal of 398157669 is 966751893.

398157669 is a `hidden beast` number, since 3 + 9 + 8 + 1 + 576 + 69 = 666.

It is not a de Polignac number, because 398157669 - 2⁴ = 398157653 is a prime.

It is a super-2 number, since 2×398157669² = 317059058767027122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398157659) 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 in 71 ways as a sum of consecutive naturals, for example, 432792 + ... + 433710.

Almost surely, 2^398157669 is an apocalyptic number.

398157669 is a gapful number since it is divisible by the number (39) formed by its first and last digit.

It is an amenable number.

398157669 is a deficient number, since it is larger than the sum of its proper divisors (342596891).

398157669 is a wasteful number, since it uses less digits than its factorization.

398157669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 991 (or 965 counting only the distinct ones).

The product of its digits is 2449440, while the sum is 54.

The square root of 398157669 is about 19953.8885683969. Note that the first 3 decimals coincide. The cubic root of 398157669 is about 735.6733576593.

The spelling of 398157669 in words is "three hundred ninety-eight million, one hundred fifty-seven thousand, six hundred sixty-nine".