28739866 has 4 divisors (see below), whose sum is σ = 43109802. Its totient is φ = 14369932.

The previous prime is 28739863. The next prime is 28739873. The reversal of 28739866 is 66893782.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66893782 = 2 ⋅33446891.

It can be written as a sum of positive squares in only one way, i.e., 17816841 + 10923025 = 4221^2 + 3305^2 .

It is not an unprimeable number, because it can be changed into a prime (28739863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7184965 + ... + 7184968.

Almost surely, 2^28739866 is an apocalyptic number.

28739866 is a deficient number, since it is larger than the sum of its proper divisors (14369936).

28739866 is a wasteful number, since it uses less digits than its factorization.

28739866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14369935.

The product of its digits is 870912, while the sum is 49.

The square root of 28739866 is about 5360.9575637194. The cubic root of 28739866 is about 306.3102851750.

The spelling of 28739866 in words is "twenty-eight million, seven hundred thirty-nine thousand, eight hundred sixty-six".