28315421 has 12 divisors (see below), whose sum is σ = 30467772. Its totient is φ = 26222976.

The previous prime is 28315381. The next prime is 28315423. The reversal of 28315421 is 12451382.

It can be written as a sum of positive squares in 2 ways, for example, as 15319396 + 12996025 = 3914^2 + 3605^2 .

It is a de Polignac number, because none of the positive numbers 2^k-28315421 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 (28315423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 180275 + ... + 180431.

It is an arithmetic number, because the mean of its divisors is an integer number (2538981).

Almost surely, 2^28315421 is an apocalyptic number.

It is an amenable number.

28315421 is a deficient number, since it is larger than the sum of its proper divisors (2152351).

28315421 is a wasteful number, since it uses less digits than its factorization.

28315421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 380 (or 277 counting only the distinct ones).

The product of its digits is 1920, while the sum is 26.

The square root of 28315421 is about 5321.2236374729. The cubic root of 28315421 is about 304.7948849326.

The spelling of 28315421 in words is "twenty-eight million, three hundred fifteen thousand, four hundred twenty-one".