3661931857920 has 768 divisors, whose sum is σ = 14139111168000. Its totient is φ = 790401908736.

The previous prime is 3661931857891. The next prime is 3661931857931. The reversal of 3661931857920 is 297581391663.

It is a tau number, because it is divible by the number of its divisors (768).

It is a Harshad number since it is a multiple of its sum of digits (60).

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, 1442272011 + ... + 1442274549.

It is an arithmetic number, because the mean of its divisors is an integer number (18410301000).

Almost surely, 2^{3661931857920} is an apocalyptic number.

3661931857920 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 3661931857920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7069555584000).

3661931857920 is an abundant number, since it is smaller than the sum of its proper divisors (10477179310080).

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

3661931857920 is a wasteful number, since it uses less digits than its factorization.

3661931857920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2948 (or 2928 counting only the distinct ones).

The product of its (nonzero) digits is 14696640, while the sum is 60.

The spelling of 3661931857920 in words is "three trillion, six hundred sixty-one billion, nine hundred thirty-one million, eight hundred fifty-seven thousand, nine hundred twenty".