20040397 has 8 divisors (see below), whose sum is σ = 21825720. Its totient is φ = 18289920.

The previous prime is 20040373. The next prime is 20040403. The reversal of 20040397 is 79304002.

It can be written as a sum of positive squares in 4 ways, for example, as 139876 + 19900521 = 374^2 + 4461^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20040397 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 (20040197) by changing a digit.

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, 7504 + ... + 9817.

It is an arithmetic number, because the mean of its divisors is an integer number (2728215).

Almost surely, 2^20040397 is an apocalyptic number.

It is an amenable number.

20040397 is a deficient number, since it is larger than the sum of its proper divisors (1785323).

20040397 is a wasteful number, since it uses less digits than its factorization.

20040397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17423.

The product of its (nonzero) digits is 1512, while the sum is 25.

The square root of 20040397 is about 4476.6501985301. The cubic root of 20040397 is about 271.6243959641.

Adding to 20040397 its reverse (79304002), we get a palindrome (99344399).

The spelling of 20040397 in words is "twenty million, forty thousand, three hundred ninety-seven".