2665623281 has 2 divisors, whose sum is σ = 2665623282. Its totient is φ = 2665623280.

The previous prime is 2665623229. The next prime is 2665623383. The reversal of 2665623281 is 1823265662.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2066157025 + 599466256 = 45455^2 + 24484^2 .

It is a cyclic number.

It is not a de Polignac number, because 2665623281 - 2⁶ = 2665623217 is a prime.

It is a super-2 number, since 2×2665623281² = 14211094952418409922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2665623581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1332811640 + 1332811641.

It is an arithmetic number, because the mean of its divisors is an integer number (1332811641).

Almost surely, 2^2665623281 is an apocalyptic number.

It is an amenable number.

2665623281 is a deficient number, since it is larger than the sum of its proper divisors (1).

2665623281 is an equidigital number, since it uses as much as digits as its factorization.

2665623281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 207360, while the sum is 41.

The square root of 2665623281 is about 51629.6744227581. The cubic root of 2665623281 is about 1386.5416643038.

The spelling of 2665623281 in words is "two billion, six hundred sixty-five million, six hundred twenty-three thousand, two hundred eighty-one".