55721417 has 2 divisors, whose sum is σ = 55721418. Its totient is φ = 55721416.

The previous prime is 55721401. The next prime is 55721423. The reversal of 55721417 is 71412755.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53860921 + 1860496 = 7339^2 + 1364^2 .

It is a cyclic number.

It is not a de Polignac number, because 55721417 - 2⁴ = 55721401 is a prime.

It is not a weakly prime, because it can be changed into another prime (55721437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27860708 + 27860709.

It is an arithmetic number, because the mean of its divisors is an integer number (27860709).

Almost surely, 2^55721417 is an apocalyptic number.

It is an amenable number.

55721417 is a deficient number, since it is larger than the sum of its proper divisors (1).

55721417 is an equidigital number, since it uses as much as digits as its factorization.

55721417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9800, while the sum is 32.

The square root of 55721417 is about 7464.6779568847. The cubic root of 55721417 is about 381.9507648321.

The spelling of 55721417 in words is "fifty-five million, seven hundred twenty-one thousand, four hundred seventeen".