20677649 has 2 divisors, whose sum is σ = 20677650. Its totient is φ = 20677648.

The previous prime is 20677639. The next prime is 20677663. The reversal of 20677649 is 94677602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20611600 + 66049 = 4540^2 + 257^2 .

It is a cyclic number.

It is not a de Polignac number, because 20677649 - 2²⁰ = 19629073 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20677619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10338824 + 10338825.

It is an arithmetic number, because the mean of its divisors is an integer number (10338825).

Almost surely, 2^20677649 is an apocalyptic number.

It is an amenable number.

20677649 is a deficient number, since it is larger than the sum of its proper divisors (1).

20677649 is an equidigital number, since it uses as much as digits as its factorization.

20677649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 127008, while the sum is 41.

The square root of 20677649 is about 4547.2683008593. The cubic root of 20677649 is about 274.4734785033.

The spelling of 20677649 in words is "twenty million, six hundred seventy-seven thousand, six hundred forty-nine".