28361421 has 40 divisors (see below), whose sum is σ = 46754400. Its totient is φ = 16990560.

The previous prime is 28361387. The next prime is 28361453. The reversal of 28361421 is 12416382.

28361421 is a `hidden beast` number, since 28 + 3 + 614 + 21 = 666.

It is not a de Polignac number, because 28361421 - 2⁷ = 28361293 is a prime.

It is a super-2 number, since 2×28361421² = 1608740402278482, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28368421) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 123735 + ... + 123963.

It is an arithmetic number, because the mean of its divisors is an integer number (1168860).

Almost surely, 2^28361421 is an apocalyptic number.

It is an amenable number.

28361421 is a deficient number, since it is larger than the sum of its proper divisors (18392979).

28361421 is a wasteful number, since it uses less digits than its factorization.

28361421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 391 (or 382 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 28361421 is about 5325.5441975445. The cubic root of 28361421 is about 304.9598478004.

It can be divided in two parts, 28361 and 421, that added together give a palindrome (28782).

The spelling of 28361421 in words is "twenty-eight million, three hundred sixty-one thousand, four hundred twenty-one".