398988618 has 64 divisors (see below), whose sum is σ = 939091968. Its totient is φ = 110658240.

The previous prime is 398988607. The next prime is 398988637. The reversal of 398988618 is 816889893.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 198796 + ... + 200792.

It is an arithmetic number, because the mean of its divisors is an integer number (14673312).

Almost surely, 2^398988618 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 398988618, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (469545984).

398988618 is an abundant number, since it is smaller than the sum of its proper divisors (540103350).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

398988618 is a wasteful number, since it uses less digits than its factorization.

398988618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2147.

The product of its digits is 5971968, while the sum is 60.

The square root of 398988618 is about 19974.6994470505. The cubic root of 398988618 is about 736.1847817491.

It can be divided in two parts, 39898 and 8618, that added together give a triangular number (48516 = T₃₁₁).

The spelling of 398988618 in words is "three hundred ninety-eight million, nine hundred eighty-eight thousand, six hundred eighteen".