1990492605 has 12 divisors (see below), whose sum is σ = 3450187260. Its totient is φ = 1061596032.

The previous prime is 1990492579. The next prime is 1990492607. The reversal of 1990492605 is 5062940991.

1990492605 is a `hidden beast` number, since 19 + 90 + 492 + 60 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 830477124 + 1160015481 = 28818^2 + 34059^2 .

It is not a de Polignac number, because 1990492605 - 2⁶ = 1990492541 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 44233169 = 1990492605 / (1 + 9 + 9 + 0 + 4 + 9 + 2 + 6 + 0 + 5).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990492607) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22116540 + ... + 22116629.

It is an arithmetic number, because the mean of its divisors is an integer number (287515605).

Almost surely, 2^1990492605 is an apocalyptic number.

1990492605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1990492605 is a deficient number, since it is larger than the sum of its proper divisors (1459694655).

1990492605 is a wasteful number, since it uses less digits than its factorization.

1990492605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44233180 (or 44233177 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 45.

The square root of 1990492605 is about 44614.9370166540. The cubic root of 1990492605 is about 1257.9214501940.

The spelling of 1990492605 in words is "one billion, nine hundred ninety million, four hundred ninety-two thousand, six hundred five".