399971973960 has 192 divisors, whose sum is σ = 1401604167600. Its totient is φ = 98334922752.

The previous prime is 399971973949. The next prime is 399971973977. The reversal of 399971973960 is 69379179993.

399971973960 is a `hidden beast` number, since 399 + 97 + 1 + 97 + 3 + 9 + 60 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 112883904324 + 287088069636 = 335982^2 + 535806^2 .

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3828174 + ... + 3931266.

Almost surely, 2^399971973960 is an apocalyptic number.

399971973960 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 399971973960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (700802083800).

399971973960 is an abundant number, since it is smaller than the sum of its proper divisors (1001632193640).

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

399971973960 is a wasteful number, since it uses less digits than its factorization.

399971973960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103952 (or 103945 counting only the distinct ones).

The product of its (nonzero) digits is 156243654, while the sum is 72.

The spelling of 399971973960 in words is "three hundred ninety-nine billion, nine hundred seventy-one million, nine hundred seventy-three thousand, nine hundred sixty".