1631640155491 has 8 divisors (see below), whose sum is σ = 1632865136400. Its totient is φ = 1630415535840.

The previous prime is 1631640155477. The next prime is 1631640155527. The reversal of 1631640155491 is 1945510461361.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1631640155491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1631640155461) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9310465 + ... + 9484093.

It is an arithmetic number, because the mean of its divisors is an integer number (204108142050).

Almost surely, 2^{1631640155491} is an apocalyptic number.

1631640155491 is a deficient number, since it is larger than the sum of its proper divisors (1224980909).

1631640155491 is a wasteful number, since it uses less digits than its factorization.

1631640155491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180629.

The product of its (nonzero) digits is 388800, while the sum is 46.

The spelling of 1631640155491 in words is "one trillion, six hundred thirty-one billion, six hundred forty million, one hundred fifty-five thousand, four hundred ninety-one".