20430399 has 16 divisors (see below), whose sum is σ = 29940480. Its totient is φ = 12288960.

The previous prime is 20430373. The next prime is 20430409. The reversal of 20430399 is 99303402.

It is a Cunningham number, because it is equal to 4520²-1.

It is not a de Polignac number, because 20430399 - 2⁸ = 20430143 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20430349) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2262 + ... + 6780.

It is an arithmetic number, because the mean of its divisors is an integer number (1871280).

Almost surely, 2^20430399 is an apocalyptic number.

20430399 is a deficient number, since it is larger than the sum of its proper divisors (9510081).

20430399 is a wasteful number, since it uses less digits than its factorization.

20430399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4670.

The product of its (nonzero) digits is 5832, while the sum is 30.

The square root of 20430399 is about 4519.9998893805. Note that the first 3 decimals coincide. The cubic root of 20430399 is about 273.3750965666.

It can be divided in two parts, 204303 and 99, that added together give a palindrome (204402).

The spelling of 20430399 in words is "twenty million, four hundred thirty thousand, three hundred ninety-nine".