1631917609 has 27 divisors (see below), whose sum is σ = 1976000247. Its totient is φ = 1343765808.

The previous prime is 1631917603. The next prime is 1631917613. The reversal of 1631917609 is 9067191361.

The square root of 1631917609 is 40397.

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

It can be written as a sum of positive squares in only one way, i.e., 855738009 + 776179600 = 29253^2 + 27860^2 .

It is not a de Polignac number, because 1631917609 - 2⁵ = 1631917577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1631917603) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 8200492 + ... + 8200690.

Almost surely, 2^1631917609 is an apocalyptic number.

1631917609 is the 40397-th square number.

1631917609 is the 20199-th centered octagonal number.

It is an amenable number.

1631917609 is a deficient number, since it is larger than the sum of its proper divisors (344082638).

1631917609 is an frugal number, since it uses more digits than its factorization.

1631917609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 470 (or 235 counting only the distinct ones).

The product of its (nonzero) digits is 61236, while the sum is 43.

The cubic root of 1631917609 is about 1177.3332502785. Note that the first 3 decimals are identical.

The spelling of 1631917609 in words is "one billion, six hundred thirty-one million, nine hundred seventeen thousand, six hundred nine".