21440533453 has 2 divisors, whose sum is σ = 21440533454. Its totient is φ = 21440533452.

The previous prime is 21440533427. The next prime is 21440533469. The reversal of 21440533453 is 35433504412.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20973411684 + 467121769 = 144822^2 + 21613^2 .

It is a cyclic number.

It is not a de Polignac number, because 21440533453 - 2¹³ = 21440525261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21440533423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10720266726 + 10720266727.

It is an arithmetic number, because the mean of its divisors is an integer number (10720266727).

Almost surely, 2^21440533453 is an apocalyptic number.

It is an amenable number.

21440533453 is a deficient number, since it is larger than the sum of its proper divisors (1).

21440533453 is an equidigital number, since it uses as much as digits as its factorization.

21440533453 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 86400, while the sum is 34.

The spelling of 21440533453 in words is "twenty-one billion, four hundred forty million, five hundred thirty-three thousand, four hundred fifty-three".