72101261 has 2 divisors, whose sum is σ = 72101262. Its totient is φ = 72101260.

The previous prime is 72101209. The next prime is 72101287. The reversal of 72101261 is 16210127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68376361 + 3724900 = 8269^2 + 1930^2 .

It is an emirp because it is prime and its reverse (16210127) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72101261 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72101291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36050630 + 36050631.

It is an arithmetic number, because the mean of its divisors is an integer number (36050631).

Almost surely, 2^72101261 is an apocalyptic number.

It is an amenable number.

72101261 is a deficient number, since it is larger than the sum of its proper divisors (1).

72101261 is an equidigital number, since it uses as much as digits as its factorization.

72101261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 72101261 is about 8491.2461394073. The cubic root of 72101261 is about 416.2117022964.

Adding to 72101261 its reverse (16210127), we get a palindrome (88311388).

It can be divided in two parts, 7210126 and 1, that added together give a palindrome (7210127).

The spelling of 72101261 in words is "seventy-two million, one hundred one thousand, two hundred sixty-one".