21180579851 has 2 divisors, whose sum is σ = 21180579852. Its totient is φ = 21180579850.

The previous prime is 21180579757. The next prime is 21180579857. The reversal of 21180579851 is 15897508112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21180579851 - 2²² = 21176385547 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21180579796 and 21180579805.

It is not a weakly prime, because it can be changed into another prime (21180579857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10590289925 + 10590289926.

It is an arithmetic number, because the mean of its divisors is an integer number (10590289926).

Almost surely, 2^21180579851 is an apocalyptic number.

21180579851 is a deficient number, since it is larger than the sum of its proper divisors (1).

21180579851 is an equidigital number, since it uses as much as digits as its factorization.

21180579851 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 201600, while the sum is 47.

The spelling of 21180579851 in words is "twenty-one billion, one hundred eighty million, five hundred seventy-nine thousand, eight hundred fifty-one".