2021522664397 has 2 divisors, whose sum is σ = 2021522664398. Its totient is φ = 2021522664396.

The previous prime is 2021522664391. The next prime is 2021522664409. The reversal of 2021522664397 is 7934662251202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1839335400841 + 182187263556 = 1356221^2 + 426834^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2021522664397 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2021522664397.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021522664391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010761332198 + 1010761332199.

It is an arithmetic number, because the mean of its divisors is an integer number (1010761332199).

Almost surely, 2^{2021522664397} is an apocalyptic number.

It is an amenable number.

2021522664397 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021522664397 is an equidigital number, since it uses as much as digits as its factorization.

2021522664397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2177280, while the sum is 49.

The spelling of 2021522664397 in words is "two trillion, twenty-one billion, five hundred twenty-two million, six hundred sixty-four thousand, three hundred ninety-seven".