20722687 has 2 divisors, whose sum is σ = 20722688. Its totient is φ = 20722686.

The previous prime is 20722661. The next prime is 20722769. The reversal of 20722687 is 78622702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20722687 - 2²³ = 12334079 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20722987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10361343 + 10361344.

It is an arithmetic number, because the mean of its divisors is an integer number (10361344).

Almost surely, 2^20722687 is an apocalyptic number.

20722687 is a deficient number, since it is larger than the sum of its proper divisors (1).

20722687 is an equidigital number, since it uses as much as digits as its factorization.

20722687 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18816, while the sum is 34.

The square root of 20722687 is about 4552.2178111334. The cubic root of 20722687 is about 274.6726109471.

The spelling of 20722687 in words is "twenty million, seven hundred twenty-two thousand, six hundred eighty-seven".