72665261 has 2 divisors, whose sum is σ = 72665262. Its totient is φ = 72665260.

The previous prime is 72665251. The next prime is 72665267. The reversal of 72665261 is 16256627.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68641225 + 4024036 = 8285^2 + 2006^2 .

It is an emirp because it is prime and its reverse (16256627) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72665261 - 2²² = 68470957 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72665267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36332630 + 36332631.

It is an arithmetic number, because the mean of its divisors is an integer number (36332631).

Almost surely, 2^72665261 is an apocalyptic number.

It is an amenable number.

72665261 is a deficient number, since it is larger than the sum of its proper divisors (1).

72665261 is an equidigital number, since it uses as much as digits as its factorization.

72665261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 35.

The square root of 72665261 is about 8524.3921190898. The cubic root of 72665261 is about 417.2941335083.

The spelling of 72665261 in words is "seventy-two million, six hundred sixty-five thousand, two hundred sixty-one".