20726647 has 2 divisors, whose sum is σ = 20726648. Its totient is φ = 20726646.

The previous prime is 20726627. The next prime is 20726653. The reversal of 20726647 is 74662702.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20726647 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20726617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10363323 + 10363324.

It is an arithmetic number, because the mean of its divisors is an integer number (10363324).

Almost surely, 2^20726647 is an apocalyptic number.

20726647 is a deficient number, since it is larger than the sum of its proper divisors (1).

20726647 is an equidigital number, since it uses as much as digits as its factorization.

20726647 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 34.

The square root of 20726647 is about 4552.6527431817. The cubic root of 20726647 is about 274.6901060120.

The spelling of 20726647 in words is "twenty million, seven hundred twenty-six thousand, six hundred forty-seven".