20649789 has 16 divisors (see below), whose sum is σ = 32203200. Its totient is φ = 13041648.

The previous prime is 20649767. The next prime is 20649803. The reversal of 20649789 is 98794602.

It is a happy number.

It is not a de Polignac number, because 20649789 - 2⁵ = 20649757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20649709) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19614 + ... + 20639.

It is an arithmetic number, because the mean of its divisors is an integer number (2012700).

Almost surely, 2^20649789 is an apocalyptic number.

It is an amenable number.

20649789 is a deficient number, since it is larger than the sum of its proper divisors (11553411).

20649789 is a wasteful number, since it uses less digits than its factorization.

20649789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40281 (or 40275 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 20649789 is about 4544.2038906722. The cubic root of 20649789 is about 274.3501526197.

The spelling of 20649789 in words is "twenty million, six hundred forty-nine thousand, seven hundred eighty-nine".