52072721 has 2 divisors, whose sum is σ = 52072722. Its totient is φ = 52072720.

The previous prime is 52072697. The next prime is 52072723. The reversal of 52072721 is 12727025.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47059600 + 5013121 = 6860^2 + 2239^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-52072721 is a prime.

Together with 52072723, 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 (52072723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26036360 + 26036361.

It is an arithmetic number, because the mean of its divisors is an integer number (26036361).

Almost surely, 2^52072721 is an apocalyptic number.

It is an amenable number.

52072721 is a deficient number, since it is larger than the sum of its proper divisors (1).

52072721 is an equidigital number, since it uses as much as digits as its factorization.

52072721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1960, while the sum is 26.

The square root of 52072721 is about 7216.1430833930. The cubic root of 52072721 is about 373.4250294710.

Adding to 52072721 its reverse (12727025), we get a palindrome (64799746).

The spelling of 52072721 in words is "fifty-two million, seventy-two thousand, seven hundred twenty-one".