19621899779 has 8 divisors (see below), whose sum is σ = 20256582528. Its totient is φ = 18987324480.

The previous prime is 19621899769. The next prime is 19621899821. The reversal of 19621899779 is 97799812691.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19621899779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19621899709) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 523679 + ... + 559895.

It is an arithmetic number, because the mean of its divisors is an integer number (2532072816).

Almost surely, 2^19621899779 is an apocalyptic number.

19621899779 is a deficient number, since it is larger than the sum of its proper divisors (634682749).

19621899779 is a wasteful number, since it uses less digits than its factorization.

19621899779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53725.

The product of its digits is 30862944, while the sum is 68.

The spelling of 19621899779 in words is "nineteen billion, six hundred twenty-one million, eight hundred ninety-nine thousand, seven hundred seventy-nine".