28292921 has 4 divisors (see below), whose sum is σ = 29523072. Its totient is φ = 27062772.

The previous prime is 28292917. The next prime is 28292923. The reversal of 28292921 is 12929282.

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 28292921 - 2² = 28292917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28292923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 615041 + ... + 615086.

It is an arithmetic number, because the mean of its divisors is an integer number (7380768).

Almost surely, 2^28292921 is an apocalyptic number.

It is an amenable number.

28292921 is a deficient number, since it is larger than the sum of its proper divisors (1230151).

28292921 is a wasteful number, since it uses less digits than its factorization.

28292921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1230150.

The product of its digits is 10368, while the sum is 35.

The square root of 28292921 is about 5319.1090419355. The cubic root of 28292921 is about 304.7141315017.

The spelling of 28292921 in words is "twenty-eight million, two hundred ninety-two thousand, nine hundred twenty-one".