21180799 has 2 divisors, whose sum is σ = 21180800. Its totient is φ = 21180798.

The previous prime is 21180779. The next prime is 21180857. The reversal of 21180799 is 99708112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21180799 - 2⁹ = 21180287 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21180739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10590399 + 10590400.

It is an arithmetic number, because the mean of its divisors is an integer number (10590400).

Almost surely, 2^21180799 is an apocalyptic number.

21180799 is a deficient number, since it is larger than the sum of its proper divisors (1).

21180799 is an equidigital number, since it uses as much as digits as its factorization.

21180799 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 21180799 is about 4602.2602055946. The cubic root of 21180799 is about 276.6819192894.

The spelling of 21180799 in words is "twenty-one million, one hundred eighty thousand, seven hundred ninety-nine".