20408207 has 4 divisors (see below), whose sum is σ = 20417520. Its totient is φ = 20398896.

The previous prime is 20408191. The next prime is 20408231. The reversal of 20408207 is 70280402.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20408207 - 2⁴ = 20408191 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 (20408807) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 638 + ... + 6420.

It is an arithmetic number, because the mean of its divisors is an integer number (5104380).

Almost surely, 2^20408207 is an apocalyptic number.

20408207 is a deficient number, since it is larger than the sum of its proper divisors (9313).

20408207 is an equidigital number, since it uses as much as digits as its factorization.

20408207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9312.

The product of its (nonzero) digits is 896, while the sum is 23.

The square root of 20408207 is about 4517.5443550673. The cubic root of 20408207 is about 273.2760784631.

Adding to 20408207 its reverse (70280402), we get a palindrome (90688609).

The spelling of 20408207 in words is "twenty million, four hundred eight thousand, two hundred seven".