398891951 has 4 divisors (see below), whose sum is σ = 408168552. Its totient is φ = 389615352.

The previous prime is 398891903. The next prime is 398891957. The reversal of 398891951 is 159198893.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 398891951 - 2¹⁴ = 398875567 is a prime.

It is a super-2 number, since 2×398891951² = 318229577145172802, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 398891893 and 398891902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398891957) 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 3 ways as a sum of consecutive naturals, for example, 4638236 + ... + 4638321.

It is an arithmetic number, because the mean of its divisors is an integer number (102042138).

Almost surely, 2^398891951 is an apocalyptic number.

398891951 is a deficient number, since it is larger than the sum of its proper divisors (9276601).

398891951 is an equidigital number, since it uses as much as digits as its factorization.

398891951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9276600.

The product of its digits is 699840, while the sum is 53.

The square root of 398891951 is about 19972.2795644363. The cubic root of 398891951 is about 736.1253226408.

The spelling of 398891951 in words is "three hundred ninety-eight million, eight hundred ninety-one thousand, nine hundred fifty-one".