398863637640 has 320 divisors, whose sum is σ = 1528679219760. Its totient is φ = 92406251520.

The previous prime is 398863637639. The next prime is 398863637651. The reversal of 398863637640 is 46736368893.

It is a happy number.

398863637640 is a `hidden beast` number, since 3 + 98 + 86 + 363 + 76 + 40 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 222559384644 + 176304252996 = 471762^2 + 419886^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 437520 + ... + 994560.

Almost surely, 2^398863637640 is an apocalyptic number.

398863637640 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 398863637640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (764339609880).

398863637640 is an abundant number, since it is smaller than the sum of its proper divisors (1129815582120).

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

398863637640 is a wasteful number, since it uses less digits than its factorization.

398863637640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 557094 (or 557081 counting only the distinct ones).

The product of its (nonzero) digits is 94058496, while the sum is 63.

The spelling of 398863637640 in words is "three hundred ninety-eight billion, eight hundred sixty-three million, six hundred thirty-seven thousand, six hundred forty".