28914640 has 20 divisors (see below), whose sum is σ = 67226724. Its totient is φ = 11565824.

The previous prime is 28914631. The next prime is 28914647. The reversal of 28914640 is 4641982.

It can be written as a sum of positive squares in 2 ways, for example, as 14107536 + 14807104 = 3756^2 + 3848^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 28914596 and 28914605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28914647) 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, 180637 + ... + 180796.

Almost surely, 2^28914640 is an apocalyptic number.

28914640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28914640 is an abundant number, since it is smaller than the sum of its proper divisors (38312084).

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

28914640 is a wasteful number, since it uses less digits than its factorization.

28914640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361446 (or 361440 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 28914640 is about 5377.2334894442. The cubic root of 28914640 is about 306.9299461373.

The spelling of 28914640 in words is "twenty-eight million, nine hundred fourteen thousand, six hundred forty".