20499385 has 24 divisors (see below), whose sum is σ = 26691336. Its totient is φ = 15102720.

The previous prime is 20499383. The next prime is 20499389. The reversal of 20499385 is 58399402.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 393129 + 20106256 = 627^2 + 4484^2 .

It is not a de Polignac number, because 20499385 - 2¹ = 20499383 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 (20499383) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 73867 + ... + 74143.

It is an arithmetic number, because the mean of its divisors is an integer number (1112139).

Almost surely, 2^20499385 is an apocalyptic number.

It is an amenable number.

20499385 is a deficient number, since it is larger than the sum of its proper divisors (6191951).

20499385 is a wasteful number, since it uses less digits than its factorization.

20499385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361 (or 342 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 40.

The square root of 20499385 is about 4527.6246531708. The cubic root of 20499385 is about 273.6824468607.

The spelling of 20499385 in words is "twenty million, four hundred ninety-nine thousand, three hundred eighty-five".