28012638 has 8 divisors (see below), whose sum is σ = 56025288. Its totient is φ = 9337544.

The previous prime is 28012627. The next prime is 28012639. The reversal of 28012638 is 83621082.

It is a sphenic number, since it is the product of 3 distinct primes.

28012638 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28012639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2334381 + ... + 2334392.

It is an arithmetic number, because the mean of its divisors is an integer number (7003161).

Almost surely, 2^28012638 is an apocalyptic number.

28012638 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

28012638 is a wasteful number, since it uses less digits than its factorization.

28012638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4668778.

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 28012638 is about 5292.6966661618. The cubic root of 28012638 is about 303.7045765198.

The spelling of 28012638 in words is "twenty-eight million, twelve thousand, six hundred thirty-eight".