19649858641 has 4 divisors (see below), whose sum is σ = 22456981312. Its totient is φ = 16842735972.

The previous prime is 19649858639. The next prime is 19649858659. The reversal of 19649858641 is 14685894691.

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.

It is a cyclic number.

It is not a de Polignac number, because 19649858641 - 2¹ = 19649858639 is a prime.

It is a super-2 number, since 2×19649858641² (a number of 21 digits) contains 22 as substring.

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 19649858641.

It is not an unprimeable number, because it can be changed into a prime (19649858611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1403561325 + ... + 1403561338.

It is an arithmetic number, because the mean of its divisors is an integer number (5614245328).

Almost surely, 2^19649858641 is an apocalyptic number.

It is an amenable number.

19649858641 is a deficient number, since it is larger than the sum of its proper divisors (2807122671).

19649858641 is an equidigital number, since it uses as much as digits as its factorization.

19649858641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2807122670.

The product of its digits is 14929920, while the sum is 61.

The spelling of 19649858641 in words is "nineteen billion, six hundred forty-nine million, eight hundred fifty-eight thousand, six hundred forty-one".