19977479869 has 2 divisors, whose sum is σ = 19977479870. Its totient is φ = 19977479868.

The previous prime is 19977479843. The next prime is 19977479891. The reversal of 19977479869 is 96897477991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10437074244 + 9540405625 = 102162^2 + 97675^2 .

It is a cyclic number.

It is not a de Polignac number, because 19977479869 - 2²¹ = 19975382717 is a prime.

It is a super-2 number, since 2×19977479869² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19977479795 and 19977479804.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19977479839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9988739934 + 9988739935.

It is an arithmetic number, because the mean of its divisors is an integer number (9988739935).

Almost surely, 2^19977479869 is an apocalyptic number.

It is an amenable number.

19977479869 is a deficient number, since it is larger than the sum of its proper divisors (1).

19977479869 is an equidigital number, since it uses as much as digits as its factorization.

19977479869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432081216, while the sum is 76.

The spelling of 19977479869 in words is "nineteen billion, nine hundred seventy-seven million, four hundred seventy-nine thousand, eight hundred sixty-nine".