28400540 has 48 divisors (see below), whose sum is σ = 72176832. Its totient is φ = 9163776.

The previous prime is 28400539. The next prime is 28400543. The reversal of 28400540 is 4500482.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28400543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3587 + ... + 8346.

It is an arithmetic number, because the mean of its divisors is an integer number (1503684).

Almost surely, 2^28400540 is an apocalyptic number.

28400540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28400540 is an abundant number, since it is smaller than the sum of its proper divisors (43776292).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28400540 is a wasteful number, since it uses less digits than its factorization.

28400540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11966 (or 11964 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 23.

The square root of 28400540 is about 5329.2157021460. The cubic root of 28400540 is about 305.0999940879.

The spelling of 28400540 in words is "twenty-eight million, four hundred thousand, five hundred forty".