398375640 has 192 divisors, whose sum is σ = 1455330240. Its totient is φ = 93772800.

The previous prime is 398375623. The next prime is 398375647. The reversal of 398375640 is 46573893.

398375640 is a `hidden beast` number, since 3 + 9 + 83 + 7 + 564 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398375647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 105790 + ... + 109490.

It is an arithmetic number, because the mean of its divisors is an integer number (7579845).

Almost surely, 2^398375640 is an apocalyptic number.

398375640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 398375640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (727665120).

398375640 is an abundant number, since it is smaller than the sum of its proper divisors (1056954600).

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

398375640 is a wasteful number, since it uses less digits than its factorization.

398375640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3754 (or 3747 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The square root of 398375640 is about 19959.3496888050. The cubic root of 398375640 is about 735.8075810392.

The spelling of 398375640 in words is "three hundred ninety-eight million, three hundred seventy-five thousand, six hundred forty".