398161998 has 96 divisors (see below), whose sum is σ = 994436352. Its totient is φ = 114048000.

The previous prime is 398161991. The next prime is 398161999. The reversal of 398161998 is 899161893.

398161998 is a `hidden beast` number, since 398 + 161 + 9 + 98 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398161991) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 401283 + ... + 402273.

It is an arithmetic number, because the mean of its divisors is an integer number (10358712).

Almost surely, 2^398161998 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 398161998, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (497218176).

398161998 is an abundant number, since it is smaller than the sum of its proper divisors (596274354).

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

398161998 is a wasteful number, since it uses less digits than its factorization.

398161998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1130 (or 1127 counting only the distinct ones).

The product of its digits is 839808, while the sum is 54.

The square root of 398161998 is about 19953.9970431991. The cubic root of 398161998 is about 735.6760238714.

It can be divided in two parts, 39816 and 1998, that added together give a palindrome (41814).

The spelling of 398161998 in words is "three hundred ninety-eight million, one hundred sixty-one thousand, nine hundred ninety-eight".