28950781 has 4 divisors (see below), whose sum is σ = 29159200. Its totient is φ = 28742364.

The previous prime is 28950743. The next prime is 28950821. The reversal of 28950781 is 18705982.

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 28950781 - 2²³ = 20562173 is a prime.

It is a super-2 number, since 2×28950781² = 1676295441019922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28920781) 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, 104001 + ... + 104278.

It is an arithmetic number, because the mean of its divisors is an integer number (7289800).

Almost surely, 2^28950781 is an apocalyptic number.

It is an amenable number.

28950781 is a deficient number, since it is larger than the sum of its proper divisors (208419).

28950781 is a wasteful number, since it uses less digits than its factorization.

28950781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208418.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 28950781 is about 5380.5929970590. The cubic root of 28950781 is about 307.0577722340.

The spelling of 28950781 in words is "twenty-eight million, nine hundred fifty thousand, seven hundred eighty-one".