28661994 has 48 divisors (see below), whose sum is σ = 66924000. Its totient is φ = 8836128.

The previous prime is 28661981. The next prime is 28661999. The reversal of 28661994 is 49916682.

It is a happy number.

28661994 is a `hidden beast` number, since 28 + 6 + 619 + 9 + 4 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (28661999) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13732 + ... + 15680.

It is an arithmetic number, because the mean of its divisors is an integer number (1394250).

Almost surely, 2^28661994 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28661994, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33462000).

28661994 is an abundant number, since it is smaller than the sum of its proper divisors (38262006).

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

28661994 is a wasteful number, since it uses less digits than its factorization.

28661994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2019 (or 2016 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 28661994 is about 5353.6897556732. The cubic root of 28661994 is about 306.0333809541.

The spelling of 28661994 in words is "twenty-eight million, six hundred sixty-one thousand, nine hundred ninety-four".