20872261 has 2 divisors, whose sum is σ = 20872262. Its totient is φ = 20872260.

The previous prime is 20872249. The next prime is 20872273. The reversal of 20872261 is 16227802.

20872261 = 3230² + 3231².

It is a balanced prime because it is at equal distance from previous prime (20872249) and next prime (20872273).

It can be written as a sum of positive squares in only one way, i.e., 10439361 + 10432900 = 3231^2 + 3230^2 .

It is a cyclic number.

It is not a de Polignac number, because 20872261 - 2⁷ = 20872133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20872211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10436130 + 10436131.

It is an arithmetic number, because the mean of its divisors is an integer number (10436131).

Almost surely, 2^20872261 is an apocalyptic number.

20872261 is the 3231-st centered square number.

It is an amenable number.

20872261 is a deficient number, since it is larger than the sum of its proper divisors (1).

20872261 is an equidigital number, since it uses as much as digits as its factorization.

20872261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 20872261 is about 4568.6169679674. The cubic root of 20872261 is about 275.3318792058.

The spelling of 20872261 in words is "twenty million, eight hundred seventy-two thousand, two hundred sixty-one".