20111261 has 2 divisors, whose sum is σ = 20111262. Its totient is φ = 20111260.

The previous prime is 20111257. The next prime is 20111293. The reversal of 20111261 is 16211102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10686361 + 9424900 = 3269^2 + 3070^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111261 - 2² = 20111257 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20117261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055630 + 10055631.

It is an arithmetic number, because the mean of its divisors is an integer number (10055631).

Almost surely, 2^20111261 is an apocalyptic number.

It is an amenable number.

20111261 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111261 is an equidigital number, since it uses as much as digits as its factorization.

20111261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 14.

The square root of 20111261 is about 4484.5580607235. The cubic root of 20111261 is about 271.9441791808.

Adding to 20111261 its reverse (16211102), we get a palindrome (36322363).

The spelling of 20111261 in words is "twenty million, one hundred eleven thousand, two hundred sixty-one".