641781979545 has 64 divisors (see below), whose sum is σ = 1226386022400. Its totient is φ = 280465936128.

The previous prime is 641781979529. The next prime is 641781979571. The reversal of 641781979545 is 545979187146.

It is not a de Polignac number, because 641781979545 - 2⁴ = 641781979529 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1299970 + ... + 1724379.

It is an arithmetic number, because the mean of its divisors is an integer number (19162281600).

Almost surely, 2^641781979545 is an apocalyptic number.

It is an amenable number.

641781979545 is a deficient number, since it is larger than the sum of its proper divisors (584604042855).

641781979545 is a wasteful number, since it uses less digits than its factorization.

641781979545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3024454.

The product of its digits is 76204800, while the sum is 66.

The spelling of 641781979545 in words is "six hundred forty-one billion, seven hundred eighty-one million, nine hundred seventy-nine thousand, five hundred forty-five".