20865461 has 2 divisors, whose sum is σ = 20865462. Its totient is φ = 20865460.

The previous prime is 20865391. The next prime is 20865463. The reversal of 20865461 is 16456802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19802500 + 1062961 = 4450^2 + 1031^2 .

It is a cyclic number.

It is not a de Polignac number, because 20865461 - 2¹⁴ = 20849077 is a prime.

Together with 20865463, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_1321988 and since 20865461 and 1321988 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20865463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10432730 + 10432731.

It is an arithmetic number, because the mean of its divisors is an integer number (10432731).

Almost surely, 2^20865461 is an apocalyptic number.

It is an amenable number.

20865461 is a deficient number, since it is larger than the sum of its proper divisors (1).

20865461 is an equidigital number, since it uses as much as digits as its factorization.

20865461 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 20865461 is about 4567.8726996273. The cubic root of 20865461 is about 275.3019757191.

The spelling of 20865461 in words is "twenty million, eight hundred sixty-five thousand, four hundred sixty-one".