180772721 has 2 divisors, whose sum is σ = 180772722. Its totient is φ = 180772720.

The previous prime is 180772703. The next prime is 180772723. The reversal of 180772721 is 127277081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 178489600 + 2283121 = 13360^2 + 1511^2 .

It is a cyclic number.

It is not a de Polignac number, because 180772721 - 2²² = 176578417 is a prime.

Together with 180772723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (180772723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90386360 + 90386361.

It is an arithmetic number, because the mean of its divisors is an integer number (90386361).

Almost surely, 2^180772721 is an apocalyptic number.

It is an amenable number.

180772721 is a deficient number, since it is larger than the sum of its proper divisors (1).

180772721 is an equidigital number, since it uses as much as digits as its factorization.

180772721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10976, while the sum is 35.

The square root of 180772721 is about 13445.1746362775. The cubic root of 180772721 is about 565.4284175929.

The spelling of 180772721 in words is "one hundred eighty million, seven hundred seventy-two thousand, seven hundred twenty-one".