20609397 has 10 divisors (see below), whose sum is σ = 30786998. Its totient is φ = 13739544.

The previous prime is 20609387. The next prime is 20609411. The reversal of 20609397 is 79390602.

It can be written as a sum of positive squares in only one way, i.e., 13024881 + 7584516 = 3609^2 + 2754^2 .

It is not a de Polignac number, because 20609397 - 2⁷ = 20609269 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 (20609387) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 127138 + ... + 127299.

Almost surely, 2^20609397 is an apocalyptic number.

20609397 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

20609397 is a deficient number, since it is larger than the sum of its proper divisors (10177601).

20609397 is an equidigital number, since it uses as much as digits as its factorization.

20609397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254449 (or 254440 counting only the distinct ones).

The product of its (nonzero) digits is 20412, while the sum is 36.

The square root of 20609397 is about 4539.7573723713. The cubic root of 20609397 is about 274.1711550752.

Adding to 20609397 its reverse (79390602), we get a palindrome (99999999).

The spelling of 20609397 in words is "twenty million, six hundred nine thousand, three hundred ninety-seven".