1990684615680 has 1232 divisors, whose sum is σ = 7669528798320. Its totient is φ = 493810089984.

The previous prime is 1990684615657. The next prime is 1990684615723. The reversal of 1990684615680 is 865164860991.

1990684615680 is a `hidden beast` number, since 1 + 9 + 9 + 0 + 6 + 8 + 4 + 61 + 568 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 275045704704 + 1715638910976 = 524448^2 + 1309824^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 8692945806 + ... + 8692946034.

Almost surely, 2^{1990684615680} is an apocalyptic number.

1990684615680 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 1990684615680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3834764399160).

1990684615680 is an abundant number, since it is smaller than the sum of its proper divisors (5678844182640).

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

1990684615680 is a wasteful number, since it uses less digits than its factorization.

1990684615680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426 (or 393 counting only the distinct ones).

The product of its (nonzero) digits is 22394880, while the sum is 63.

The spelling of 1990684615680 in words is "one trillion, nine hundred ninety billion, six hundred eighty-four million, six hundred fifteen thousand, six hundred eighty".