72770161 has 2 divisors, whose sum is σ = 72770162. Its totient is φ = 72770160.

The previous prime is 72770143. The next prime is 72770177. The reversal of 72770161 is 16107727.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50680161 + 22090000 = 7119^2 + 4700^2 .

It is a cyclic number.

It is not a de Polignac number, because 72770161 - 2¹⁵ = 72737393 is a prime.

It is not a weakly prime, because it can be changed into another prime (72770141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36385080 + 36385081.

It is an arithmetic number, because the mean of its divisors is an integer number (36385081).

Almost surely, 2^72770161 is an apocalyptic number.

It is an amenable number.

72770161 is a deficient number, since it is larger than the sum of its proper divisors (1).

72770161 is an equidigital number, since it uses as much as digits as its factorization.

72770161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4116, while the sum is 31.

The square root of 72770161 is about 8530.5428314967. The cubic root of 72770161 is about 417.4948397177.

Adding to 72770161 its reverse (16107727), we get a palindrome (88877888).

The spelling of 72770161 in words is "seventy-two million, seven hundred seventy thousand, one hundred sixty-one".