21241655999 has 2 divisors, whose sum is σ = 21241656000. Its totient is φ = 21241655998.

The previous prime is 21241655971. The next prime is 21241656019. The reversal of 21241655999 is 99955614212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21241655999 - 2¹² = 21241651903 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21241655999.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21241655909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10620827999 + 10620828000.

It is an arithmetic number, because the mean of its divisors is an integer number (10620828000).

Almost surely, 2^21241655999 is an apocalyptic number.

21241655999 is a deficient number, since it is larger than the sum of its proper divisors (1).

21241655999 is an equidigital number, since it uses as much as digits as its factorization.

21241655999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1749600, while the sum is 53.

The spelling of 21241655999 in words is "twenty-one billion, two hundred forty-one million, six hundred fifty-five thousand, nine hundred ninety-nine".