20028997 has 2 divisors, whose sum is σ = 20028998. Its totient is φ = 20028996.

The previous prime is 20028991. The next prime is 20029019. The reversal of 20028997 is 79982002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20016676 + 12321 = 4474^2 + 111^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20028997 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20028991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10014498 + 10014499.

It is an arithmetic number, because the mean of its divisors is an integer number (10014499).

Almost surely, 2^20028997 is an apocalyptic number.

It is an amenable number.

20028997 is a deficient number, since it is larger than the sum of its proper divisors (1).

20028997 is an equidigital number, since it uses as much as digits as its factorization.

20028997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 20028997 is about 4475.3767439178. The cubic root of 20028997 is about 271.5728815912.

It can be divided in two parts, 20028 and 997, that added together give a square (21025 = 145²).

The spelling of 20028997 in words is "twenty million, twenty-eight thousand, nine hundred ninety-seven".