20779571 has 2 divisors, whose sum is σ = 20779572. Its totient is φ = 20779570.

The previous prime is 20779567. The next prime is 20779609. The reversal of 20779571 is 17597702.

It is an a-pointer prime, because the next prime (20779609) can be obtained adding 20779571 to its sum of digits (38).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20779571 - 2² = 20779567 is a prime.

It is not a weakly prime, because it can be changed into another prime (20779531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10389785 + 10389786.

It is an arithmetic number, because the mean of its divisors is an integer number (10389786).

Almost surely, 2^20779571 is an apocalyptic number.

20779571 is a deficient number, since it is larger than the sum of its proper divisors (1).

20779571 is an equidigital number, since it uses as much as digits as its factorization.

20779571 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30870, while the sum is 38.

The square root of 20779571 is about 4558.4614729095. The cubic root of 20779571 is about 274.9237077621.

The spelling of 20779571 in words is "twenty million, seven hundred seventy-nine thousand, five hundred seventy-one".