1636622641 has 4 divisors (see below), whose sum is σ = 1636719984. Its totient is φ = 1636525300.

The previous prime is 1636622621. The next prime is 1636622681. The reversal of 1636622641 is 1462266361.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1636622641 - 2⁹ = 1636622129 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1636622641.

It is not an unprimeable number, because it can be changed into a prime (1636622621) 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 3 ways as a sum of consecutive naturals, for example, 16255 + ... + 59476.

It is an arithmetic number, because the mean of its divisors is an integer number (409179996).

Almost surely, 2^1636622641 is an apocalyptic number.

It is an amenable number.

1636622641 is a deficient number, since it is larger than the sum of its proper divisors (97343).

1636622641 is an equidigital number, since it uses as much as digits as its factorization.

1636622641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97342.

The product of its digits is 62208, while the sum is 37.

The square root of 1636622641 is about 40455.1930041126. The cubic root of 1636622641 is about 1178.4636332303.

The spelling of 1636622641 in words is "one billion, six hundred thirty-six million, six hundred twenty-two thousand, six hundred forty-one".