20399417 has 4 divisors (see below), whose sum is σ = 20445300. Its totient is φ = 20353536.

The previous prime is 20399411. The next prime is 20399429. The reversal of 20399417 is 71499302.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17673616 + 2725801 = 4204^2 + 1651^2 .

It is a cyclic number.

It is not a de Polignac number, because 20399417 - 2¹⁰ = 20398393 is a prime.

It is a super-2 number, since 2×20399417² = 832272427879778, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20399411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22268 + ... + 23165.

It is an arithmetic number, because the mean of its divisors is an integer number (5111325).

Almost surely, 2^20399417 is an apocalyptic number.

It is an amenable number.

20399417 is a deficient number, since it is larger than the sum of its proper divisors (45883).

20399417 is an equidigital number, since it uses as much as digits as its factorization.

20399417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45882.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 20399417 is about 4516.5713766086. The cubic root of 20399417 is about 273.2368386664.

The spelling of 20399417 in words is "twenty million, three hundred ninety-nine thousand, four hundred seventeen".