3969931979520 has 2880 divisors, whose sum is σ = 17518991745024. Its totient is φ = 851363758080.

The previous prime is 3969931979483. The next prime is 3969931979527. The reversal of 3969931979520 is 259791399693.

3969931979520 is a `hidden beast` number, since 3 + 9 + 6 + 9 + 9 + 3 + 1 + 97 + 9 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (2880).

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

It is not an unprimeable number, because it can be changed into a prime (3969931979527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 128062321905 + ... + 128062321935.

Almost surely, 2^{3969931979520} is an apocalyptic number.

3969931979520 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 3969931979520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8759495872512).

3969931979520 is an abundant number, since it is smaller than the sum of its proper divisors (13549059765504).

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

3969931979520 is an equidigital number, since it uses as much as digits as its factorization.

3969931979520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132 (or 94 counting only the distinct ones).

The product of its (nonzero) digits is 223205220, while the sum is 72.

The spelling of 3969931979520 in words is "three trillion, nine hundred sixty-nine billion, nine hundred thirty-one million, nine hundred seventy-nine thousand, five hundred twenty".