28140644 has 24 divisors (see below), whose sum is σ = 59592960. Its totient is φ = 11350656.

The previous prime is 28140641. The next prime is 28140647. The reversal of 28140644 is 44604182.

It is an interprime number because it is at equal distance from previous prime (28140641) and next prime (28140647).

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

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29084 + ... + 30035.

It is an arithmetic number, because the mean of its divisors is an integer number (2483040).

Almost surely, 2^28140644 is an apocalyptic number.

It is an amenable number.

28140644 is an abundant number, since it is smaller than the sum of its proper divisors (31452316).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28140644 is a wasteful number, since it uses less digits than its factorization.

28140644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59147 (or 59145 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 29.

The square root of 28140644 is about 5304.7755843202. The cubic root of 28140644 is about 304.1664744937.

The spelling of 28140644 in words is "twenty-eight million, one hundred forty thousand, six hundred forty-four".