19894421955 has 16 divisors (see below), whose sum is σ = 33703491744. Its totient is φ = 9986219520.

The previous prime is 19894421933. The next prime is 19894421969. The reversal of 19894421955 is 55912449891.

It is a de Polignac number, because none of the positive numbers 2^k-19894421955 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19894421895 and 19894421904.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39008416 + ... + 39008925.

It is an arithmetic number, because the mean of its divisors is an integer number (2106468234).

Almost surely, 2^19894421955 is an apocalyptic number.

19894421955 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

19894421955 is a deficient number, since it is larger than the sum of its proper divisors (13809069789).

19894421955 is a wasteful number, since it uses less digits than its factorization.

19894421955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78017366.

The product of its digits is 4665600, while the sum is 57.

The spelling of 19894421955 in words is "nineteen billion, eight hundred ninety-four million, four hundred twenty-one thousand, nine hundred fifty-five".