28400487 has 4 divisors (see below), whose sum is σ = 37867320. Its totient is φ = 18933656.

The previous prime is 28400473. The next prime is 28400503. The reversal of 28400487 is 78400482.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28400487 - 2¹⁰ = 28399463 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28400447) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4733412 + ... + 4733417.

It is an arithmetic number, because the mean of its divisors is an integer number (9466830).

Almost surely, 2^28400487 is an apocalyptic number.

28400487 is a deficient number, since it is larger than the sum of its proper divisors (9466833).

28400487 is an equidigital number, since it uses as much as digits as its factorization.

28400487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9466832.

The product of its (nonzero) digits is 14336, while the sum is 33.

The square root of 28400487 is about 5329.2107295546. The cubic root of 28400487 is about 305.0998042991.

The spelling of 28400487 in words is "twenty-eight million, four hundred thousand, four hundred eighty-seven".