1631689938 has 18 divisors (see below), whose sum is σ = 3535699557. Its totient is φ = 543839520.

The previous prime is 1631689933. The next prime is 1631689951. The reversal of 1631689938 is 8399861361.

It can be written as a sum of positive squares in 2 ways, for example, as 1625944329 + 5745609 = 40323^2 + 2397^2 .

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

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=28563.

It is not an unprimeable number, because it can be changed into a prime (1631689933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 166618 + ... + 176138.

Almost surely, 2^1631689938 is an apocalyptic number.

1631689938 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1631689938 is an abundant number, since it is smaller than the sum of its proper divisors (1904009619).

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

1631689938 is an frugal number, since it uses more digits than its factorization.

1631689938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19050 (or 9526 counting only the distinct ones).

The product of its digits is 1679616, while the sum is 54.

The square root of 1631689938 is about 40394.1819820627. The cubic root of 1631689938 is about 1177.2784972887.

The spelling of 1631689938 in words is "one billion, six hundred thirty-one million, six hundred eighty-nine thousand, nine hundred thirty-eight".