20512997 has 4 divisors (see below), whose sum is σ = 21013356. Its totient is φ = 20012640.

The previous prime is 20512991. The next prime is 20513011. The reversal of 20512997 is 79921502.

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 923521 + 19589476 = 961^2 + 4426^2 .

It is a cyclic number.

It is not a de Polignac number, because 20512997 - 2⁴ = 20512981 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 (20512991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 250118 + ... + 250199.

It is an arithmetic number, because the mean of its divisors is an integer number (5253339).

Almost surely, 2^20512997 is an apocalyptic number.

It is an amenable number.

20512997 is a deficient number, since it is larger than the sum of its proper divisors (500359).

20512997 is an equidigital number, since it uses as much as digits as its factorization.

20512997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500358.

The product of its (nonzero) digits is 11340, while the sum is 35.

The square root of 20512997 is about 4529.1276201935. The cubic root of 20512997 is about 273.7430103231.

The spelling of 20512997 in words is "twenty million, five hundred twelve thousand, nine hundred ninety-seven".