28816820 has 24 divisors (see below), whose sum is σ = 60669000. Its totient is φ = 11497472.

The previous prime is 28816817. The next prime is 28816847. The reversal of 28816820 is 2861882.

It can be written as a sum of positive squares in 4 ways, for example, as 4571044 + 24245776 = 2138^2 + 4924^2 .

It is a super-2 number, since 2×28816820² = 1660818229824800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7376 + ... + 10584.

It is an arithmetic number, because the mean of its divisors is an integer number (2527875).

Almost surely, 2^28816820 is an apocalyptic number.

28816820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28816820 is an abundant number, since it is smaller than the sum of its proper divisors (31852180).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28816820 is a wasteful number, since it uses less digits than its factorization.

28816820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3667 (or 3665 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 35.

The square root of 28816820 is about 5368.1300282314. The cubic root of 28816820 is about 306.5834341437.

The spelling of 28816820 in words is "twenty-eight million, eight hundred sixteen thousand, eight hundred twenty".