20430397 has 4 divisors (see below), whose sum is σ = 22001980. Its totient is φ = 18858816.

The previous prime is 20430373. The next prime is 20430409. The reversal of 20430397 is 79303402.

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 1819801 + 18610596 = 1349^2 + 4314^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20430397 is a prime.

It is a super-5 number, since 5×20430397⁵ (a number of 38 digits) contains 55555 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20430307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 785772 + ... + 785797.

It is an arithmetic number, because the mean of its divisors is an integer number (5500495).

Almost surely, 2^20430397 is an apocalyptic number.

It is an amenable number.

20430397 is a deficient number, since it is larger than the sum of its proper divisors (1571583).

20430397 is a wasteful number, since it uses less digits than its factorization.

20430397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1571582.

The product of its (nonzero) digits is 4536, while the sum is 28.

The square root of 20430397 is about 4519.9996681416. Note that the first 3 decimals coincide. The cubic root of 20430397 is about 273.3750876460.

Adding to 20430397 its reverse (79303402), we get a palindrome (99733799).

The spelling of 20430397 in words is "twenty million, four hundred thirty thousand, three hundred ninety-seven".