28020451 has 4 divisors (see below), whose sum is σ = 28063504. Its totient is φ = 27977400.

The previous prime is 28020449. The next prime is 28020479. The reversal of 28020451 is 15402082.

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

It is a cyclic number.

It is not a de Polignac number, because 28020451 - 2¹ = 28020449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28020401) 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, 20535 + ... + 21856.

It is an arithmetic number, because the mean of its divisors is an integer number (7015876).

Almost surely, 2^28020451 is an apocalyptic number.

28020451 is a deficient number, since it is larger than the sum of its proper divisors (43053).

28020451 is an equidigital number, since it uses as much as digits as its factorization.

28020451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43052.

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 28020451 is about 5293.4347072577. The cubic root of 28020451 is about 303.7328092920.

The spelling of 28020451 in words is "twenty-eight million, twenty thousand, four hundred fifty-one".