398215755 has 24 divisors (see below), whose sum is σ = 788847072. Its totient is φ = 182041344.

The previous prime is 398215711. The next prime is 398215877. The reversal of 398215755 is 557512893.

It is not a de Polignac number, because 398215755 - 2¹² = 398211659 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 398215755.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 631774 + ... + 632403.

It is an arithmetic number, because the mean of its divisors is an integer number (32868628).

Almost surely, 2^398215755 is an apocalyptic number.

398215755 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

398215755 is a deficient number, since it is larger than the sum of its proper divisors (390631317).

398215755 is a wasteful number, since it uses less digits than its factorization.

398215755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1264195 (or 1264192 counting only the distinct ones).

The product of its digits is 378000, while the sum is 45.

The square root of 398215755 is about 19955.3440210887. The cubic root of 398215755 is about 735.7091309623.

It can be divided in two parts, 398 and 215755, that added together give a triangular number (216153 = T₆₅₇).

The spelling of 398215755 in words is "three hundred ninety-eight million, two hundred fifteen thousand, seven hundred fifty-five".