21254999993 has 2 divisors, whose sum is σ = 21254999994. Its totient is φ = 21254999992.

The previous prime is 21254999977. The next prime is 21255000017. The reversal of 21254999993 is 39999945212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20299695529 + 955304464 = 142477^2 + 30908^2 .

It is a cyclic number.

It is not a de Polignac number, because 21254999993 - 2⁴ = 21254999977 is a prime.

It is not a weakly prime, because it can be changed into another prime (21254999693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10627499996 + 10627499997.

It is an arithmetic number, because the mean of its divisors is an integer number (10627499997).

Almost surely, 2^21254999993 is an apocalyptic number.

It is an amenable number.

21254999993 is a deficient number, since it is larger than the sum of its proper divisors (1).

21254999993 is an equidigital number, since it uses as much as digits as its factorization.

21254999993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14171760, while the sum is 62.

The spelling of 21254999993 in words is "twenty-one billion, two hundred fifty-four million, nine hundred ninety-nine thousand, nine hundred ninety-three".