21142254449 has 2 divisors, whose sum is σ = 21142254450. Its totient is φ = 21142254448.

The previous prime is 21142254443. The next prime is 21142254457. The reversal of 21142254449 is 94445224112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20886030400 + 256224049 = 144520^2 + 16007^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21142254449 is a prime.

It is not a weakly prime, because it can be changed into another prime (21142254443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571127224 + 10571127225.

It is an arithmetic number, because the mean of its divisors is an integer number (10571127225).

Almost surely, 2^21142254449 is an apocalyptic number.

It is an amenable number.

21142254449 is a deficient number, since it is larger than the sum of its proper divisors (1).

21142254449 is an equidigital number, since it uses as much as digits as its factorization.

21142254449 is an evil number, because the sum of its binary digits is even.

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

The spelling of 21142254449 in words is "twenty-one billion, one hundred forty-two million, two hundred fifty-four thousand, four hundred forty-nine".