20493649 has 6 divisors (see below), whose sum is σ = 22526210. Its totient is φ = 18630480.

The previous prime is 20493637. The next prime is 20493659. The reversal of 20493649 is 94639402.

It can be written as a sum of positive squares in only one way, i.e., 18122049 + 2371600 = 4257^2 + 1540^2 .

It is not a de Polignac number, because 20493649 - 2⁷ = 20493521 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20493659) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 84564 + ... + 84805.

Almost surely, 2^20493649 is an apocalyptic number.

It is an amenable number.

20493649 is a deficient number, since it is larger than the sum of its proper divisors (2032561).

20493649 is a wasteful number, since it uses less digits than its factorization.

20493649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169391 (or 169380 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 37.

The square root of 20493649 is about 4526.9911641177. The cubic root of 20493649 is about 273.6569178191.

Subtracting 20493649 from its reverse (94639402), we obtain a triangular number (74145753 = T₁₂₁₇₇).

The spelling of 20493649 in words is "twenty million, four hundred ninety-three thousand, six hundred forty-nine".