398323640 has 128 divisors (see below), whose sum is σ = 1066867200. Its totient is φ = 131934720.

The previous prime is 398323621. The next prime is 398323661. The reversal of 398323640 is 46323893.

It is a junction number, because it is equal to n+sod(n) for n = 398323594 and 398323603.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 474341 + ... + 475179.

It is an arithmetic number, because the mean of its divisors is an integer number (8334900).

Almost surely, 2^398323640 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 398323640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (533433600).

398323640 is an abundant number, since it is smaller than the sum of its proper divisors (668543560).

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

398323640 is a wasteful number, since it uses less digits than its factorization.

398323640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 957 (or 953 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 38.

The square root of 398323640 is about 19958.0469986419. The cubic root of 398323640 is about 735.7755646412.

The spelling of 398323640 in words is "three hundred ninety-eight million, three hundred twenty-three thousand, six hundred forty".