20769649 has 2 divisors, whose sum is σ = 20769650. Its totient is φ = 20769648.

The previous prime is 20769643. The next prime is 20769689. The reversal of 20769649 is 94696702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11424400 + 9345249 = 3380^2 + 3057^2 .

It is a cyclic number.

It is not a de Polignac number, because 20769649 - 2⁷ = 20769521 is a prime.

It is not a weakly prime, because it can be changed into another prime (20769643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10384824 + 10384825.

It is an arithmetic number, because the mean of its divisors is an integer number (10384825).

Almost surely, 2^20769649 is an apocalyptic number.

It is an amenable number.

20769649 is a deficient number, since it is larger than the sum of its proper divisors (1).

20769649 is an equidigital number, since it uses as much as digits as its factorization.

20769649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 163296, while the sum is 43.

The square root of 20769649 is about 4557.3730371783. The cubic root of 20769649 is about 274.8799431867.

The spelling of 20769649 in words is "twenty million, seven hundred sixty-nine thousand, six hundred forty-nine".