20390497 has 4 divisors (see below), whose sum is σ = 21589956. Its totient is φ = 19191040.

The previous prime is 20390483. The next prime is 20390549. The reversal of 20390497 is 79409302.

20390497 = 56⁴ + 57⁴.

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 9834496 + 10556001 = 3136^2 + 3249^2 .

It is a cyclic number.

It is not a de Polignac number, because 20390497 - 2¹¹ = 20388449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20390197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 599704 + ... + 599737.

It is an arithmetic number, because the mean of its divisors is an integer number (5397489).

Almost surely, 2^20390497 is an apocalyptic number.

It is an amenable number.

20390497 is a deficient number, since it is larger than the sum of its proper divisors (1199459).

20390497 is a wasteful number, since it uses less digits than its factorization.

20390497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1199458.

The product of its (nonzero) digits is 13608, while the sum is 34.

The square root of 20390497 is about 4515.5837939296. The cubic root of 20390497 is about 273.1970070063.

Adding to 20390497 its reverse (79409302), we get a palindrome (99799799).

It can be divided in two parts, 203 and 90497, that multiplied together give a triangular number (18370891 = T₆₀₆₁).

The spelling of 20390497 in words is "twenty million, three hundred ninety thousand, four hundred ninety-seven".