1611991680 has 512 divisors, whose sum is σ = 6107270400. Its totient is φ = 357826560.

The previous prime is 1611991657. The next prime is 1611991699. The reversal of 1611991680 is 861991161.

It is a happy number.

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, 12305215 + ... + 12305345.

Almost surely, 2^1611991680 is an apocalyptic number.

1611991680 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 1611991680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3053635200).

1611991680 is an abundant number, since it is smaller than the sum of its proper divisors (4495278720).

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

1611991680 is a wasteful number, since it uses less digits than its factorization.

1611991680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212 (or 200 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 42.

The square root of 1611991680 is about 40149.6161874556. The cubic root of 1611991680 is about 1172.5218160373.

The spelling of 1611991680 in words is "one billion, six hundred eleven million, nine hundred ninety-one thousand, six hundred eighty".