866153026644421 has 2 divisors, whose sum is σ = 866153026644422. Its totient is φ = 866153026644420.

The previous prime is 866153026644391. The next prime is 866153026644427. The reversal of 866153026644421 is 124446620351668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 811484955230625 + 54668071413796 = 28486575^2 + 7393786^2 .

It is a cyclic number.

It is not a de Polignac number, because 866153026644421 - 2⁷ = 866153026644293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866153026644427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433076513322210 + 433076513322211.

It is an arithmetic number, because the mean of its divisors is an integer number (433076513322211).

Almost surely, 2^{866153026644421} is an apocalyptic number.

It is an amenable number.

866153026644421 is a deficient number, since it is larger than the sum of its proper divisors (1).

866153026644421 is an equidigital number, since it uses as much as digits as its factorization.

866153026644421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 39813120, while the sum is 58.

The spelling of 866153026644421 in words is "eight hundred sixty-six trillion, one hundred fifty-three billion, twenty-six million, six hundred forty-four thousand, four hundred twenty-one".