2665565465221 has 2 divisors, whose sum is σ = 2665565465222. Its totient is φ = 2665565465220.

The previous prime is 2665565465201. The next prime is 2665565465243. The reversal of 2665565465221 is 1225645655662.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1730379762721 + 935185702500 = 1315439^2 + 967050^2 .

It is a cyclic number.

It is not a de Polignac number, because 2665565465221 - 2²³ = 2665557076613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2665565465201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1332782732610 + 1332782732611.

It is an arithmetic number, because the mean of its divisors is an integer number (1332782732611).

Almost surely, 2^{2665565465221} is an apocalyptic number.

It is an amenable number.

2665565465221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2665565465221 is an equidigital number, since it uses as much as digits as its factorization.

2665565465221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25920000, while the sum is 55.

The spelling of 2665565465221 in words is "two trillion, six hundred sixty-five billion, five hundred sixty-five million, four hundred sixty-five thousand, two hundred twenty-one".