399649620191640 has 256 divisors, whose sum is σ = 1475851234636800. Its totient is φ = 84308999952384.

The previous prime is 399649620191623. The next prime is 399649620191669. The reversal of 399649620191640 is 46191026946993.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 69968274 + ... + 75464286.

It is an arithmetic number, because the mean of its divisors is an integer number (5765043885300).

Almost surely, 2^{399649620191640} is an apocalyptic number.

399649620191640 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 399649620191640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (737925617318400).

399649620191640 is an abundant number, since it is smaller than the sum of its proper divisors (1076201614445160).

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

399649620191640 is a wasteful number, since it uses less digits than its factorization.

399649620191640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5502706 (or 5502702 counting only the distinct ones).

The product of its (nonzero) digits is 136048896, while the sum is 69.

The spelling of 399649620191640 in words is "three hundred ninety-nine trillion, six hundred forty-nine billion, six hundred twenty million, one hundred ninety-one thousand, six hundred forty".