28621399 has 2 divisors, whose sum is σ = 28621400. Its totient is φ = 28621398.

The previous prime is 28621393. The next prime is 28621427. The reversal of 28621399 is 99312682.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28621399 - 2⁵ = 28621367 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28621393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14310699 + 14310700.

It is an arithmetic number, because the mean of its divisors is an integer number (14310700).

Almost surely, 2^28621399 is an apocalyptic number.

28621399 is a deficient number, since it is larger than the sum of its proper divisors (1).

28621399 is an equidigital number, since it uses as much as digits as its factorization.

28621399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46656, while the sum is 40.

The square root of 28621399 is about 5349.8971018142. The cubic root of 28621399 is about 305.8888307067. Note that the first 4 decimals are identical.

The spelling of 28621399 in words is "twenty-eight million, six hundred twenty-one thousand, three hundred ninety-nine".