28527981 has 12 divisors (see below), whose sum is σ = 39752928. Its totient is φ = 18163464.

The previous prime is 28527959. The next prime is 28528007. The reversal of 28527981 is 18972582.

It is not a de Polignac number, because 28527981 - 2¹¹ = 28525933 is a prime.

It is a super-2 number, since 2×28527981² = 1627691399872722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28527901) 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, 44046 + ... + 44688.

It is an arithmetic number, because the mean of its divisors is an integer number (3312744).

Almost surely, 2^28527981 is an apocalyptic number.

It is an amenable number.

28527981 is a deficient number, since it is larger than the sum of its proper divisors (11224947).

28527981 is an frugal number, since it uses more digits than its factorization.

28527981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1312 (or 669 counting only the distinct ones).

The product of its digits is 80640, while the sum is 42.

The square root of 28527981 is about 5341.1591438563. The cubic root of 28527981 is about 305.5556689268. Note that the first 3 decimals are identical.

The spelling of 28527981 in words is "twenty-eight million, five hundred twenty-seven thousand, nine hundred eighty-one".