19857724641 has 16 divisors (see below), whose sum is σ = 29422393600. Its totient is φ = 13236889104.

The previous prime is 19857724631. The next prime is 19857724643. The reversal of 19857724641 is 14642775891.

19857724641 is a `hidden beast` number, since 1 + 9 + 8 + 577 + 2 + 4 + 64 + 1 = 666.

It is not a de Polignac number, because 19857724641 - 2⁹ = 19857724129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19857724643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 210840 + ... + 290118.

It is an arithmetic number, because the mean of its divisors is an integer number (1838899600).

Almost surely, 2^19857724641 is an apocalyptic number.

It is an amenable number.

19857724641 is a deficient number, since it is larger than the sum of its proper divisors (9564668959).

19857724641 is an equidigital number, since it uses as much as digits as its factorization.

19857724641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88565 (or 88559 counting only the distinct ones).

The product of its digits is 3386880, while the sum is 54.

The spelling of 19857724641 in words is "nineteen billion, eight hundred fifty-seven million, seven hundred twenty-four thousand, six hundred forty-one".