21243076957499 has 16 divisors (see below), whose sum is σ = 21716642808000. Its totient is φ = 20772264779136.

The previous prime is 21243076957493. The next prime is 21243076957507. The reversal of 21243076957499 is 99475967034212.

It is a cyclic number.

It is not a de Polignac number, because 21243076957499 - 2²⁴ = 21243060180283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21243076957493) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37247402 + ... + 37813424.

It is an arithmetic number, because the mean of its divisors is an integer number (1357290175500).

Almost surely, 2^{21243076957499} is an apocalyptic number.

21243076957499 is a deficient number, since it is larger than the sum of its proper divisors (473565850501).

21243076957499 is a wasteful number, since it uses less digits than its factorization.

21243076957499 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 568454.

The product of its (nonzero) digits is 205752960, while the sum is 68.

The spelling of 21243076957499 in words is "twenty-one trillion, two hundred forty-three billion, seventy-six million, nine hundred fifty-seven thousand, four hundred ninety-nine".