20442661 has 2 divisors, whose sum is σ = 20442662. Its totient is φ = 20442660.

The previous prime is 20442659. The next prime is 20442691. The reversal of 20442661 is 16624402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17181025 + 3261636 = 4145^2 + 1806^2 .

It is a cyclic number.

It is not a de Polignac number, because 20442661 - 2¹ = 20442659 is a prime.

Together with 20442659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20442691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10221330 + 10221331.

It is an arithmetic number, because the mean of its divisors is an integer number (10221331).

Almost surely, 2^20442661 is an apocalyptic number.

It is an amenable number.

20442661 is a deficient number, since it is larger than the sum of its proper divisors (1).

20442661 is an equidigital number, since it uses as much as digits as its factorization.

20442661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 20442661 is about 4521.3561018792. The cubic root of 20442661 is about 273.4297774211.

The spelling of 20442661 in words is "twenty million, four hundred forty-two thousand, six hundred sixty-one".