28451331 has 20 divisors (see below), whose sum is σ = 42741072. Its totient is φ = 18860688.

The previous prime is 28451327. The next prime is 28451359. The reversal of 28451331 is 13315482.

It is a happy number.

28451331 is a `hidden beast` number, since 284 + 51 + 331 = 666.

It is not a de Polignac number, because 28451331 - 2² = 28451327 is a prime.

It is a super-2 number, since 2×28451331² = 1618956471343122, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 28451295 and 28451304.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28456331) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 15066 + ... + 16848.

Almost surely, 2^28451331 is an apocalyptic number.

28451331 is a deficient number, since it is larger than the sum of its proper divisors (14289741).

28451331 is a wasteful number, since it uses less digits than its factorization.

28451331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1992 (or 1983 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 28451331 is about 5333.9789088447. The cubic root of 28451331 is about 305.2817641667.

It can be divided in two parts, 28451 and 331, that added together give a palindrome (28782).

The spelling of 28451331 in words is "twenty-eight million, four hundred fifty-one thousand, three hundred thirty-one".