28640207 has 2 divisors, whose sum is σ = 28640208. Its totient is φ = 28640206.

The previous prime is 28640203. The next prime is 28640231. The reversal of 28640207 is 70204682.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28640207 - 2² = 28640203 is a prime.

It is a super-2 number, since 2×28640207² = 1640522914005698, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28640207.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28640203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14320103 + 14320104.

It is an arithmetic number, because the mean of its divisors is an integer number (14320104).

Almost surely, 2^28640207 is an apocalyptic number.

28640207 is a deficient number, since it is larger than the sum of its proper divisors (1).

28640207 is an equidigital number, since it uses as much as digits as its factorization.

28640207 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 28640207 is about 5351.6546039519. The cubic root of 28640207 is about 305.9558190161.

Adding to 28640207 its reverse (70204682), we get a palindrome (98844889).

The spelling of 28640207 in words is "twenty-eight million, six hundred forty thousand, two hundred seven".