28021061 has 4 divisors (see below), whose sum is σ = 29239392. Its totient is φ = 26802732.

The previous prime is 28021057. The next prime is 28021087. The reversal of 28021061 is 16012082.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28021061 - 2² = 28021057 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28021001) 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, 609131 + ... + 609176.

It is an arithmetic number, because the mean of its divisors is an integer number (7309848).

Almost surely, 2^28021061 is an apocalyptic number.

It is an amenable number.

28021061 is a deficient number, since it is larger than the sum of its proper divisors (1218331).

28021061 is a wasteful number, since it uses less digits than its factorization.

28021061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1218330.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 28021061 is about 5293.4923254880. The cubic root of 28021061 is about 303.7350133449.

The spelling of 28021061 in words is "twenty-eight million, twenty-one thousand, sixty-one".