6399551881701 has 64 divisors (see below), whose sum is σ = 10697837230080. Its totient is φ = 3747180528000.

The previous prime is 6399551881607. The next prime is 6399551881711. The reversal of 6399551881701 is 1071881559936.

6399551881701 is a `hidden beast` number, since 6 + 3 + 9 + 9 + 551 + 8 + 8 + 1 + 70 + 1 = 666.

It is not a de Polignac number, because 6399551881701 - 2⁷ = 6399551881573 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6399551881711) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1296955 + ... + 3805416.

It is an arithmetic number, because the mean of its divisors is an integer number (167153706720).

Almost surely, 2^{6399551881701} is an apocalyptic number.

It is an amenable number.

6399551881701 is a deficient number, since it is larger than the sum of its proper divisors (4298285348379).

6399551881701 is a wasteful number, since it uses less digits than its factorization.

6399551881701 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5102535 (or 5102529 counting only the distinct ones).

The product of its (nonzero) digits is 16329600, while the sum is 63.

The spelling of 6399551881701 in words is "six trillion, three hundred ninety-nine billion, five hundred fifty-one million, eight hundred eighty-one thousand, seven hundred one".