28722686 has 4 divisors (see below), whose sum is σ = 43084032. Its totient is φ = 14361342.

The previous prime is 28722677. The next prime is 28722689. The reversal of 28722686 is 68622782.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28722689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7180670 + ... + 7180673.

It is an arithmetic number, because the mean of its divisors is an integer number (10771008).

Almost surely, 2^28722686 is an apocalyptic number.

28722686 is a deficient number, since it is larger than the sum of its proper divisors (14361346).

28722686 is a wasteful number, since it uses less digits than its factorization.

28722686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14361345.

The product of its digits is 129024, while the sum is 41.

The square root of 28722686 is about 5359.3549985050. The cubic root of 28722686 is about 306.2492380378.

The spelling of 28722686 in words is "twenty-eight million, seven hundred twenty-two thousand, six hundred eighty-six".