21453181559 has 2 divisors, whose sum is σ = 21453181560. Its totient is φ = 21453181558.

The previous prime is 21453181543. The next prime is 21453181579. The reversal of 21453181559 is 95518135412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21453181559 - 2⁴ = 21453181543 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21453181579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10726590779 + 10726590780.

It is an arithmetic number, because the mean of its divisors is an integer number (10726590780).

Almost surely, 2^21453181559 is an apocalyptic number.

21453181559 is a deficient number, since it is larger than the sum of its proper divisors (1).

21453181559 is an equidigital number, since it uses as much as digits as its factorization.

21453181559 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216000, while the sum is 44.

The spelling of 21453181559 in words is "twenty-one billion, four hundred fifty-three million, one hundred eighty-one thousand, five hundred fifty-nine".