265563240421 has 2 divisors, whose sum is σ = 265563240422. Its totient is φ = 265563240420.

The previous prime is 265563240419. The next prime is 265563240443. The reversal of 265563240421 is 124042365562.

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., 264030517921 + 1532722500 = 513839^2 + 39150^2 .

It is a cyclic number.

It is not a de Polignac number, because 265563240421 - 2¹ = 265563240419 is a prime.

Together with 265563240419, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (265563240461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 132781620210 + 132781620211.

It is an arithmetic number, because the mean of its divisors is an integer number (132781620211).

Almost surely, 2^265563240421 is an apocalyptic number.

It is an amenable number.

265563240421 is a deficient number, since it is larger than the sum of its proper divisors (1).

265563240421 is an equidigital number, since it uses as much as digits as its factorization.

265563240421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 345600, while the sum is 40.

The spelling of 265563240421 in words is "two hundred sixty-five billion, five hundred sixty-three million, two hundred forty thousand, four hundred twenty-one".