28252981 has 4 divisors (see below), whose sum is σ = 29740000. Its totient is φ = 26765964.

The previous prime is 28252979. The next prime is 28253011. The reversal of 28252981 is 18925282.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28252981 - 2¹ = 28252979 is a prime.

It is a super-2 number, since 2×28252981² = 1596461870772722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28252981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28252921) 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, 743481 + ... + 743518.

It is an arithmetic number, because the mean of its divisors is an integer number (7435000).

Almost surely, 2^28252981 is an apocalyptic number.

It is an amenable number.

28252981 is a deficient number, since it is larger than the sum of its proper divisors (1487019).

28252981 is a wasteful number, since it uses less digits than its factorization.

28252981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1487018.

The product of its digits is 23040, while the sum is 37.

The square root of 28252981 is about 5315.3533278607. The cubic root of 28252981 is about 304.5706796741.

It can be divided in two parts, 28 and 252981, that added together give a square (253009 = 503²).

The spelling of 28252981 in words is "twenty-eight million, two hundred fifty-two thousand, nine hundred eighty-one".