1991481802 has 4 divisors (see below), whose sum is σ = 2987222706. Its totient is φ = 995740900.

The previous prime is 1991481799. The next prime is 1991481851. The reversal of 1991481802 is 2081841991.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1636121601 + 355360201 = 40449^2 + 18851^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 497870449 + ... + 497870452.

Almost surely, 2^1991481802 is an apocalyptic number.

1991481802 is a deficient number, since it is larger than the sum of its proper divisors (995740904).

1991481802 is an equidigital number, since it uses as much as digits as its factorization.

1991481802 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 995740903.

The product of its (nonzero) digits is 41472, while the sum is 43.

The square root of 1991481802 is about 44626.0215793431. The cubic root of 1991481802 is about 1258.1297949442.

The spelling of 1991481802 in words is "one billion, nine hundred ninety-one million, four hundred eighty-one thousand, eight hundred two".