1661718763200 has 672 divisors, whose sum is σ = 5768741848320. Its totient is φ = 418321612800.

The previous prime is 1661718763109. The next prime is 1661718763241. The reversal of 1661718763200 is 23678171661.

It is a super-2 number, since 2×1661718763200² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 1661718763200.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 742832482 + ... + 742834718.

Almost surely, 2^{1661718763200} is an apocalyptic number.

1661718763200 is a gapful number since it is divisible by the number (10) 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 1661718763200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2884370924160).

1661718763200 is an abundant number, since it is smaller than the sum of its proper divisors (4107023085120).

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

1661718763200 is a wasteful number, since it uses less digits than its factorization.

1661718763200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2425 (or 2410 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 48.

The spelling of 1661718763200 in words is "one trillion, six hundred sixty-one billion, seven hundred eighteen million, seven hundred sixty-three thousand, two hundred".