21545541323279 has 2 divisors, whose sum is σ = 21545541323280. Its totient is φ = 21545541323278.

The previous prime is 21545541323179. The next prime is 21545541323321. The reversal of 21545541323279 is 97232314554512.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21545541323279 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21545541323279.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21545541323179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10772770661639 + 10772770661640.

It is an arithmetic number, because the mean of its divisors is an integer number (10772770661640).

Almost surely, 2^{21545541323279} is an apocalyptic number.

21545541323279 is a deficient number, since it is larger than the sum of its proper divisors (1).

21545541323279 is an equidigital number, since it uses as much as digits as its factorization.

21545541323279 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072000, while the sum is 53.

The spelling of 21545541323279 in words is "twenty-one trillion, five hundred forty-five billion, five hundred forty-one million, three hundred twenty-three thousand, two hundred seventy-nine".