1631661390 has 24 divisors (see below), whose sum is σ = 4242319848. Its totient is φ = 435109680.

The previous prime is 1631661349. The next prime is 1631661391. The reversal of 1631661390 is 931661361.

1631661390 is a `hidden beast` number, since 1 + 6 + 31 + 6 + 613 + 9 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1631661391) 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 11 ways as a sum of consecutive naturals, for example, 9064696 + ... + 9064875.

It is an arithmetic number, because the mean of its divisors is an integer number (176763327).

Almost surely, 2^1631661390 is an apocalyptic number.

1631661390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1631661390 is an abundant number, since it is smaller than the sum of its proper divisors (2610658458).

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

1631661390 is a wasteful number, since it uses less digits than its factorization.

1631661390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18129584 (or 18129581 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 1631661390 is about 40393.8286127968. The cubic root of 1631661390 is about 1177.2716313718.

The spelling of 1631661390 in words is "one billion, six hundred thirty-one million, six hundred sixty-one thousand, three hundred ninety".