20499405 has 8 divisors (see below), whose sum is σ = 32799072. Its totient is φ = 10933008.

The previous prime is 20499397. The next prime is 20499407. The reversal of 20499405 is 50499402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20499405 - 2³ = 20499397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20499407) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 683299 + ... + 683328.

It is an arithmetic number, because the mean of its divisors is an integer number (4099884).

Almost surely, 2^20499405 is an apocalyptic number.

It is an amenable number.

20499405 is a deficient number, since it is larger than the sum of its proper divisors (12299667).

20499405 is a wasteful number, since it uses less digits than its factorization.

20499405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1366635.

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 20499405 is about 4527.6268618339. The cubic root of 20499405 is about 273.6825358658.

The spelling of 20499405 in words is "twenty million, four hundred ninety-nine thousand, four hundred five".