28420172 has 24 divisors (see below), whose sum is σ = 54792192. Its totient is φ = 12790800.

The previous prime is 28420169. The next prime is 28420193. The reversal of 28420172 is 27102482.

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1397 + ... + 7667.

It is an arithmetic number, because the mean of its divisors is an integer number (2283008).

Almost surely, 2^28420172 is an apocalyptic number.

28420172 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

28420172 is a deficient number, since it is larger than the sum of its proper divisors (26372020).

28420172 is a wasteful number, since it uses less digits than its factorization.

28420172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6389 (or 6387 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 28420172 is about 5331.0573060135. The cubic root of 28420172 is about 305.1702784730.

The spelling of 28420172 in words is "twenty-eight million, four hundred twenty thousand, one hundred seventy-two".