21544231099 has 2 divisors, whose sum is σ = 21544231100. Its totient is φ = 21544231098.

The previous prime is 21544231001. The next prime is 21544231103. The reversal of 21544231099 is 99013244512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21544231099 - 2¹³ = 21544222907 is a prime.

It is not a weakly prime, because it can be changed into another prime (21544241099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10772115549 + 10772115550.

It is an arithmetic number, because the mean of its divisors is an integer number (10772115550).

Almost surely, 2^21544231099 is an apocalyptic number.

21544231099 is a deficient number, since it is larger than the sum of its proper divisors (1).

21544231099 is an equidigital number, since it uses as much as digits as its factorization.

21544231099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 40.

The spelling of 21544231099 in words is "twenty-one billion, five hundred forty-four million, two hundred thirty-one thousand, ninety-nine".