28778211 has 48 divisors (see below), whose sum is σ = 52386048. Its totient is φ = 14788800.

The previous prime is 28778171. The next prime is 28778213. The reversal of 28778211 is 11287782.

It is a happy number.

It is not a de Polignac number, because 28778211 - 2⁹ = 28777699 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28778213) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 90625 + ... + 90941.

It is an arithmetic number, because the mean of its divisors is an integer number (1091376).

Almost surely, 2^28778211 is an apocalyptic number.

28778211 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28778211 is a deficient number, since it is larger than the sum of its proper divisors (23607837).

28778211 is a wasteful number, since it uses less digits than its factorization.

28778211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472 (or 469 counting only the distinct ones).

The product of its digits is 12544, while the sum is 36.

The square root of 28778211 is about 5364.5326916704. The cubic root of 28778211 is about 306.4464519908.

The spelling of 28778211 in words is "twenty-eight million, seven hundred seventy-eight thousand, two hundred eleven".