20638849 has 27 divisors (see below), whose sum is σ = 26844321. Its totient is φ = 15809640.

The previous prime is 20638819. The next prime is 20638853. The reversal of 20638849 is 94883602.

The square root of 20638849 is 4543.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 20638849 - 2¹¹ = 20636801 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20638819) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 349782 + ... + 349840.

Almost surely, 2^20638849 is an apocalyptic number.

20638849 is the 4543-rd square number.

20638849 is the 2272-nd centered octagonal number.

It is an amenable number.

20638849 is a deficient number, since it is larger than the sum of its proper divisors (6205472).

20638849 is an equidigital number, since it uses as much as digits as its factorization.

20638849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 40.

The cubic root of 20638849 is about 274.3016949679.

Multiplying 20638849 by its product of nonzero digits (82944), we get a square (1711868691456 = 1308384²).

The spelling of 20638849 in words is "twenty million, six hundred thirty-eight thousand, eight hundred forty-nine".