20308390 has 16 divisors (see below), whose sum is σ = 37175760. Its totient is φ = 7985440.

The previous prime is 20308367. The next prime is 20308411. The reversal of 20308390 is 9380302.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 16621 + ... + 17800.

It is an arithmetic number, because the mean of its divisors is an integer number (2323485).

Almost surely, 2^20308390 is an apocalyptic number.

20308390 is a deficient number, since it is larger than the sum of its proper divisors (16867370).

20308390 is a wasteful number, since it uses less digits than its factorization.

20308390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34487.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 20308390 is about 4506.4831077016. The cubic root of 20308390 is about 272.8298169609.

Adding to 20308390 its reverse (9380302), we get a palindrome (29688692).

The spelling of 20308390 in words is "twenty million, three hundred eight thousand, three hundred ninety".