28191080 has 16 divisors (see below), whose sum is σ = 63430020. Its totient is φ = 11276416.

The previous prime is 28191011. The next prime is 28191091. The reversal of 28191080 is 8019182.

It can be written as a sum of positive squares in 2 ways, for example, as 23872996 + 4318084 = 4886^2 + 2078^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 352349 + ... + 352428.

Almost surely, 2^28191080 is an apocalyptic number.

28191080 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28191080 is an abundant number, since it is smaller than the sum of its proper divisors (35238940).

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

28191080 is a wasteful number, since it uses less digits than its factorization.

28191080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 704788 (or 704784 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 29.

The square root of 28191080 is about 5309.5272859267. The cubic root of 28191080 is about 304.3480835135.

The spelling of 28191080 in words is "twenty-eight million, one hundred ninety-one thousand, eighty".