19915610643 has 16 divisors (see below), whose sum is σ = 30456371200. Its totient is φ = 12848780520.

The previous prime is 19915610621. The next prime is 19915610647. The reversal of 19915610643 is 34601651991.

19915610643 is a `hidden beast` number, since 19 + 9 + 15 + 610 + 6 + 4 + 3 = 666.

It is not a de Polignac number, because 19915610643 - 2⁹ = 19915610131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19915610647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11896183 + ... + 11897856.

It is an arithmetic number, because the mean of its divisors is an integer number (1903523200).

Almost surely, 2^19915610643 is an apocalyptic number.

19915610643 is a deficient number, since it is larger than the sum of its proper divisors (10540760557).

19915610643 is a wasteful number, since it uses less digits than its factorization.

19915610643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23794079 (or 23794073 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 45.

The spelling of 19915610643 in words is "nineteen billion, nine hundred fifteen million, six hundred ten thousand, six hundred forty-three".