398283640 has 128 divisors (see below), whose sum is σ = 977080320. Its totient is φ = 145728000.

The previous prime is 398283631. The next prime is 398283647. The reversal of 398283640 is 46382893.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398283647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2637565 + ... + 2637715.

It is an arithmetic number, because the mean of its divisors is an integer number (7633440).

Almost surely, 2^398283640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 398283640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (488540160).

398283640 is an abundant number, since it is smaller than the sum of its proper divisors (578796680).

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

398283640 is a wasteful number, since it uses less digits than its factorization.

398283640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293 (or 289 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 43.

The square root of 398283640 is about 19957.0448714232. The cubic root of 398283640 is about 735.7509347466.

The spelling of 398283640 in words is "three hundred ninety-eight million, two hundred eighty-three thousand, six hundred forty".