21254421449 has 2 divisors, whose sum is σ = 21254421450. Its totient is φ = 21254421448.

The previous prime is 21254421431. The next prime is 21254421481. The reversal of 21254421449 is 94412445212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21237815824 + 16605625 = 145732^2 + 4075^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21254421449 is a prime.

It is a super-2 number, since 2×21254421449² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21254441449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10627210724 + 10627210725.

It is an arithmetic number, because the mean of its divisors is an integer number (10627210725).

Almost surely, 2^21254421449 is an apocalyptic number.

It is an amenable number.

21254421449 is a deficient number, since it is larger than the sum of its proper divisors (1).

21254421449 is an equidigital number, since it uses as much as digits as its factorization.

21254421449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 92160, while the sum is 38.

The spelling of 21254421449 in words is "twenty-one billion, two hundred fifty-four million, four hundred twenty-one thousand, four hundred forty-nine".