28140621 has 4 divisors (see below), whose sum is σ = 37520832. Its totient is φ = 18760412.

The previous prime is 28140589. The next prime is 28140641. The reversal of 28140621 is 12604182.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28140621 - 2⁵ = 28140589 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28140591 and 28140600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28140641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4690101 + ... + 4690106.

It is an arithmetic number, because the mean of its divisors is an integer number (9380208).

Almost surely, 2^28140621 is an apocalyptic number.

It is an amenable number.

28140621 is a deficient number, since it is larger than the sum of its proper divisors (9380211).

28140621 is an equidigital number, since it uses as much as digits as its factorization.

28140621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9380210.

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 28140621 is about 5304.7734164618. The cubic root of 28140621 is about 304.1663916263.

The spelling of 28140621 in words is "twenty-eight million, one hundred forty thousand, six hundred twenty-one".