20983649 has 2 divisors, whose sum is σ = 20983650. Its totient is φ = 20983648.

The previous prime is 20983643. The next prime is 20983681. The reversal of 20983649 is 94638902.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13104400 + 7879249 = 3620^2 + 2807^2 .

It is a cyclic number.

It is not a de Polignac number, because 20983649 - 2¹⁶ = 20918113 is a prime.

It is not a weakly prime, because it can be changed into another prime (20983643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10491824 + 10491825.

It is an arithmetic number, because the mean of its divisors is an integer number (10491825).

Almost surely, 2^20983649 is an apocalyptic number.

It is an amenable number.

20983649 is a deficient number, since it is larger than the sum of its proper divisors (1).

20983649 is an equidigital number, since it uses as much as digits as its factorization.

20983649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 41.

The square root of 20983649 is about 4580.7913071870. The cubic root of 20983649 is about 275.8207940152.

The spelling of 20983649 in words is "twenty million, nine hundred eighty-three thousand, six hundred forty-nine".