665655354016620 has 192 divisors, whose sum is σ = 2037556796083200. Its totient is φ = 161031330570240.

The previous prime is 665655354016603. The next prime is 665655354016643. The reversal of 665655354016620 is 26610453556566.

It is a happy number.

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, 1083876996 + ... + 1084490964.

It is an arithmetic number, because the mean of its divisors is an integer number (10612274979600).

Almost surely, 2^{665655354016620} is an apocalyptic number.

665655354016620 is a gapful number since it is divisible by the number (60) 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 665655354016620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1018778398041600).

665655354016620 is an abundant number, since it is smaller than the sum of its proper divisors (1371901442066580).

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

665655354016620 is a wasteful number, since it uses less digits than its factorization.

665655354016620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 617448 (or 617446 counting only the distinct ones).

The product of its (nonzero) digits is 116640000, while the sum is 60.

The spelling of 665655354016620 in words is "six hundred sixty-five trillion, six hundred fifty-five billion, three hundred fifty-four million, sixteen thousand, six hundred twenty".