2211551261 has 2 divisors, whose sum is σ = 2211551262. Its totient is φ = 2211551260.

The previous prime is 2211551231. The next prime is 2211551273. The reversal of 2211551261 is 1621551122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2208436036 + 3115225 = 46994^2 + 1765^2 .

It is a cyclic number.

It is not a de Polignac number, because 2211551261 - 2⁶ = 2211551197 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2211551261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2211551231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1105775630 + 1105775631.

It is an arithmetic number, because the mean of its divisors is an integer number (1105775631).

Almost surely, 2^2211551261 is an apocalyptic number.

It is an amenable number.

2211551261 is a deficient number, since it is larger than the sum of its proper divisors (1).

2211551261 is an equidigital number, since it uses as much as digits as its factorization.

2211551261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1200, while the sum is 26.

The square root of 2211551261 is about 47027.1332424166. The cubic root of 2211551261 is about 1302.8637580246.

The spelling of 2211551261 in words is "two billion, two hundred eleven million, five hundred fifty-one thousand, two hundred sixty-one".