961777981440 has 672 divisors, whose sum is σ = 3642613556400. Its totient is φ = 242939658240.

The previous prime is 961777981433. The next prime is 961777981499. The reversal of 961777981440 is 44189777169.

961777981440 is a `hidden beast` number, since 9 + 617 + 7 + 7 + 9 + 8 + 1 + 4 + 4 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 141830850 + ... + 141837630.

Almost surely, 2^961777981440 is an apocalyptic number.

961777981440 is a gapful number since it is divisible by the number (90) 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 961777981440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1821306778200).

961777981440 is an abundant number, since it is smaller than the sum of its proper divisors (2680835574960).

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

961777981440 is an equidigital number, since it uses as much as digits as its factorization.

961777981440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6845 (or 6810 counting only the distinct ones).

The product of its (nonzero) digits is 21337344, while the sum is 63.

The spelling of 961777981440 in words is "nine hundred sixty-one billion, seven hundred seventy-seven million, nine hundred eighty-one thousand, four hundred forty".