1990013661 has 12 divisors (see below), whose sum is σ = 2952152892. Its totient is φ = 1290819456.

The previous prime is 1990013657. The next prime is 1990013677. The reversal of 1990013661 is 1663100991.

It can be written as a sum of positive squares in 2 ways, for example, as 819963225 + 1170050436 = 28635^2 + 34206^2 .

It is not a de Polignac number, because 1990013661 - 2² = 1990013657 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990013261) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 2987676 + ... + 2988341.

It is an arithmetic number, because the mean of its divisors is an integer number (246012741).

Almost surely, 2^1990013661 is an apocalyptic number.

It is an amenable number.

1990013661 is a deficient number, since it is larger than the sum of its proper divisors (962139231).

1990013661 is a wasteful number, since it uses less digits than its factorization.

1990013661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5976060 (or 5976057 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 36.

The square root of 1990013661 is about 44609.5691640258. The cubic root of 1990013661 is about 1257.8205501693.

The spelling of 1990013661 in words is "one billion, nine hundred ninety million, thirteen thousand, six hundred sixty-one".