54721721 has 2 divisors, whose sum is σ = 54721722. Its totient is φ = 54721720.

The previous prime is 54721703. The next prime is 54721741. The reversal of 54721721 is 12712745.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 45751696 + 8970025 = 6764^2 + 2995^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-54721721 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (54721741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27360860 + 27360861.

It is an arithmetic number, because the mean of its divisors is an integer number (27360861).

Almost surely, 2^54721721 is an apocalyptic number.

It is an amenable number.

54721721 is a deficient number, since it is larger than the sum of its proper divisors (1).

54721721 is an equidigital number, since it uses as much as digits as its factorization.

54721721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3920, while the sum is 29.

The square root of 54721721 is about 7397.4131289255. The cubic root of 54721721 is about 379.6527783939.

The spelling of 54721721 in words is "fifty-four million, seven hundred twenty-one thousand, seven hundred twenty-one".