55546721 has 2 divisors, whose sum is σ = 55546722. Its totient is φ = 55546720.

The previous prime is 55546697. The next prime is 55546741. The reversal of 55546721 is 12764555.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53949025 + 1597696 = 7345^2 + 1264^2 .

It is a cyclic number.

It is not a de Polignac number, because 55546721 - 2¹⁰ = 55545697 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (55546741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27773360 + 27773361.

It is an arithmetic number, because the mean of its divisors is an integer number (27773361).

Almost surely, 2^55546721 is an apocalyptic number.

It is an amenable number.

55546721 is a deficient number, since it is larger than the sum of its proper divisors (1).

55546721 is an equidigital number, since it uses as much as digits as its factorization.

55546721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42000, while the sum is 35.

The square root of 55546721 is about 7452.9672614335. The cubic root of 55546721 is about 381.5511870291.

The spelling of 55546721 in words is "fifty-five million, five hundred forty-six thousand, seven hundred twenty-one".