21881509759 has 2 divisors, whose sum is σ = 21881509760. Its totient is φ = 21881509758.

The previous prime is 21881509753. The next prime is 21881509781. The reversal of 21881509759 is 95790518812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21881509759 - 2²⁷ = 21747292031 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21881509753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10940754879 + 10940754880.

It is an arithmetic number, because the mean of its divisors is an integer number (10940754880).

Almost surely, 2^21881509759 is an apocalyptic number.

21881509759 is a deficient number, since it is larger than the sum of its proper divisors (1).

21881509759 is an equidigital number, since it uses as much as digits as its factorization.

21881509759 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1814400, while the sum is 55.

The spelling of 21881509759 in words is "twenty-one billion, eight hundred eighty-one million, five hundred nine thousand, seven hundred fifty-nine".