20868461 has 2 divisors, whose sum is σ = 20868462. Its totient is φ = 20868460.

The previous prime is 20868457. The next prime is 20868473. The reversal of 20868461 is 16486802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19096900 + 1771561 = 4370^2 + 1331^2 .

It is a cyclic number.

It is not a de Polignac number, because 20868461 - 2² = 20868457 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20868451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10434230 + 10434231.

It is an arithmetic number, because the mean of its divisors is an integer number (10434231).

Almost surely, 2^20868461 is an apocalyptic number.

It is an amenable number.

20868461 is a deficient number, since it is larger than the sum of its proper divisors (1).

20868461 is an equidigital number, since it uses as much as digits as its factorization.

20868461 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 20868461 is about 4568.2010682543. The cubic root of 20868461 is about 275.3151692345.

The spelling of 20868461 in words is "twenty million, eight hundred sixty-eight thousand, four hundred sixty-one".