1990649772 has 18 divisors (see below), whose sum is σ = 5031920348. Its totient is φ = 663549912.

The previous prime is 1990649767. The next prime is 1990649807. The reversal of 1990649772 is 2779460991.

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 27647878 + ... + 27647949.

Almost surely, 2^1990649772 is an apocalyptic number.

1990649772 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1990649772 is an abundant number, since it is smaller than the sum of its proper divisors (3041270576).

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

1990649772 is a wasteful number, since it uses less digits than its factorization.

1990649772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55295837 (or 55295832 counting only the distinct ones).

The product of its (nonzero) digits is 1714608, while the sum is 54.

The square root of 1990649772 is about 44616.6983538675. The cubic root of 1990649772 is about 1257.9545573316.

The spelling of 1990649772 in words is "one billion, nine hundred ninety million, six hundred forty-nine thousand, seven hundred seventy-two".