1990855161 has 27 divisors (see below), whose sum is σ = 2923840101. Its totient is φ = 1305373464.

The previous prime is 1990855147. The next prime is 1990855177. The reversal of 1990855161 is 1615580991.

The square root of 1990855161 is 44619.

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

1990855161 is a `hidden beast` number, since 1 + 9 + 90 + 8 + 551 + 6 + 1 = 666.

It is not a de Polignac number, because 1990855161 - 2⁵ = 1990855129 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1990855561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 14322630 + ... + 14322768.

Almost surely, 2^1990855161 is an apocalyptic number.

1990855161 is the 44619-th square number.

1990855161 is the 22310-th centered octagonal number.

It is an amenable number.

1990855161 is a deficient number, since it is larger than the sum of its proper divisors (932984940).

1990855161 is an equidigital number, since it uses as much as digits as its factorization.

1990855161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 498 (or 249 counting only the distinct ones).

The product of its (nonzero) digits is 97200, while the sum is 45.

The cubic root of 1990855161 is about 1257.9978197790.

The spelling of 1990855161 in words is "one billion, nine hundred ninety million, eight hundred fifty-five thousand, one hundred sixty-one".