1991502374436 has 81 divisors (see below), whose sum is σ = 5313400820091. Its totient is φ = 628844683248.

The previous prime is 1991502374429. The next prime is 1991502374501. The reversal of 1991502374436 is 6344732051991.

The square root of 1991502374436 is 1411206.

It is a perfect power (a square), and thus also a powerful number.

1991502374436 is a `hidden beast` number, since 1 + 9 + 91 + 50 + 2 + 3 + 74 + 436 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 160871295 + ... + 160883673.

Almost surely, 2^{1991502374436} is an apocalyptic number.

1991502374436 is the 1411206-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1991502374436

1991502374436 is an abundant number, since it is smaller than the sum of its proper divisors (3321898445655).

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

1991502374436 is an equidigital number, since it uses as much as digits as its factorization.

1991502374436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24806 (or 12403 counting only the distinct ones).

The product of its (nonzero) digits is 4898880, while the sum is 54.

The spelling of 1991502374436 in words is "one trillion, nine hundred ninety-one billion, five hundred two million, three hundred seventy-four thousand, four hundred thirty-six".