28220977 has 8 divisors (see below), whose sum is σ = 29615040. Its totient is φ = 26840880.

The previous prime is 28220953. The next prime is 28220981. The reversal of 28220977 is 77902282.

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

It is a cyclic number.

It is not a de Polignac number, because 28220977 - 2⁷ = 28220849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28220917) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 774 + ... + 7552.

It is an arithmetic number, because the mean of its divisors is an integer number (3701880).

Almost surely, 2^28220977 is an apocalyptic number.

It is an amenable number.

28220977 is a deficient number, since it is larger than the sum of its proper divisors (1394063).

28220977 is a wasteful number, since it uses less digits than its factorization.

28220977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6983.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 28220977 is about 5312.3419505902. The cubic root of 28220977 is about 304.4556338448.

The spelling of 28220977 in words is "twenty-eight million, two hundred twenty thousand, nine hundred seventy-seven".