28091700 has 270 divisors, whose sum is σ = 110622694. Its totient is φ = 5927040.

The previous prime is 28091677. The next prime is 28091711. The reversal of 28091700 is 719082.

28091700 = T₁₄₂₉ + T₁₄₃₀ + ... + T₁₄₅₅.

It can be written as a sum of positive squares in 3 ways, for example, as 86436 + 28005264 = 294^2 + 5292^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 89 ways as a sum of consecutive naturals, for example, 2160894 + ... + 2160906.

Almost surely, 2^28091700 is an apocalyptic number.

28091700 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28091700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (55311347).

28091700 is an abundant number, since it is smaller than the sum of its proper divisors (82530994).

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

28091700 is a wasteful number, since it uses less digits than its factorization.

28091700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61 (or 30 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 28091700 is about 5300.1603749321. The cubic root of 28091700 is about 303.9900302594.

The spelling of 28091700 in words is "twenty-eight million, ninety-one thousand, seven hundred".