55359721 has 2 divisors, whose sum is σ = 55359722. Its totient is φ = 55359720.

The previous prime is 55359709. The next prime is 55359727. The reversal of 55359721 is 12795355.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44036496 + 11323225 = 6636^2 + 3365^2 .

It is a cyclic number.

It is not a de Polignac number, because 55359721 - 2⁷ = 55359593 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (55359727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27679860 + 27679861.

It is an arithmetic number, because the mean of its divisors is an integer number (27679861).

Almost surely, 2^55359721 is an apocalyptic number.

It is an amenable number.

55359721 is a deficient number, since it is larger than the sum of its proper divisors (1).

55359721 is an equidigital number, since it uses as much as digits as its factorization.

55359721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 47250, while the sum is 37.

The square root of 55359721 is about 7440.4113461555. The cubic root of 55359721 is about 381.1225371269.

The spelling of 55359721 in words is "fifty-five million, three hundred fifty-nine thousand, seven hundred twenty-one".