28319421 has 8 divisors (see below), whose sum is σ = 40663840. Its totient is φ = 17427312.

The previous prime is 28319419. The next prime is 28319429. The reversal of 28319421 is 12491382.

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

It is not a de Polignac number, because 28319421 - 2¹ = 28319419 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28319429) 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, 363031 + ... + 363108.

It is an arithmetic number, because the mean of its divisors is an integer number (5082980).

Almost surely, 2^28319421 is an apocalyptic number.

It is an amenable number.

28319421 is a deficient number, since it is larger than the sum of its proper divisors (12344419).

28319421 is a wasteful number, since it uses less digits than its factorization.

28319421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 726155.

The product of its digits is 3456, while the sum is 30.

The square root of 28319421 is about 5321.5994776007. The cubic root of 28319421 is about 304.8092366191.

The spelling of 28319421 in words is "twenty-eight million, three hundred nineteen thousand, four hundred twenty-one".