20500399 has 4 divisors (see below), whose sum is σ = 20699536. Its totient is φ = 20301264.

The previous prime is 20500397. The next prime is 20500423. The reversal of 20500399 is 99300502.

20500399 is nontrivially palindromic in base 7.

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

It is a cyclic number.

It is not a de Polignac number, because 20500399 - 2¹ = 20500397 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 (20500397) 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, 99414 + ... + 99619.

It is an arithmetic number, because the mean of its divisors is an integer number (5174884).

Almost surely, 2^20500399 is an apocalyptic number.

20500399 is a deficient number, since it is larger than the sum of its proper divisors (199137).

20500399 is a wasteful number, since it uses less digits than its factorization.

20500399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199136.

The product of its (nonzero) digits is 2430, while the sum is 28.

The square root of 20500399 is about 4527.7366310332. The cubic root of 20500399 is about 273.6869593445.

The spelling of 20500399 in words is "twenty million, five hundred thousand, three hundred ninety-nine".