55721201 has 2 divisors, whose sum is σ = 55721202. Its totient is φ = 55721200.

The previous prime is 55721191. The next prime is 55721207. The reversal of 55721201 is 10212755.

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., 49350625 + 6370576 = 7025^2 + 2524^2 .

It is a cyclic number.

It is not a de Polignac number, because 55721201 - 2¹⁰ = 55720177 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 (55721207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27860600 + 27860601.

It is an arithmetic number, because the mean of its divisors is an integer number (27860601).

Almost surely, 2^55721201 is an apocalyptic number.

It is an amenable number.

55721201 is a deficient number, since it is larger than the sum of its proper divisors (1).

55721201 is an equidigital number, since it uses as much as digits as its factorization.

55721201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 700, while the sum is 23.

The square root of 55721201 is about 7464.6634887314. The cubic root of 55721201 is about 381.9502712968.

Adding to 55721201 its reverse (10212755), we get a palindrome (65933956).

The spelling of 55721201 in words is "fifty-five million, seven hundred twenty-one thousand, two hundred one".