55721000213 has 2 divisors, whose sum is σ = 55721000214. Its totient is φ = 55721000212.

The previous prime is 55721000099. The next prime is 55721000221. The reversal of 55721000213 is 31200012755.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35335728484 + 20385271729 = 187978^2 + 142777^2 .

It is a cyclic number.

It is not a de Polignac number, because 55721000213 - 2¹⁰ = 55720999189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55721000263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27860500106 + 27860500107.

It is an arithmetic number, because the mean of its divisors is an integer number (27860500107).

Almost surely, 2^55721000213 is an apocalyptic number.

It is an amenable number.

55721000213 is a deficient number, since it is larger than the sum of its proper divisors (1).

55721000213 is an equidigital number, since it uses as much as digits as its factorization.

55721000213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2100, while the sum is 26.

Adding to 55721000213 its reverse (31200012755), we get a palindrome (86921012968).

The spelling of 55721000213 in words is "fifty-five billion, seven hundred twenty-one million, two hundred thirteen", and thus it is an aban number.