27861820 has 48 divisors (see below), whose sum is σ = 67834368. Its totient is φ = 9414720.

The previous prime is 27861803. The next prime is 27861829. The reversal of 27861820 is 2816872.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27861829) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8539 + ... + 11341.

It is an arithmetic number, because the mean of its divisors is an integer number (1413216).

Almost surely, 2^27861820 is an apocalyptic number.

27861820 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 27861820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33917184).

27861820 is an abundant number, since it is smaller than the sum of its proper divisors (39972548).

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

27861820 is a wasteful number, since it uses less digits than its factorization.

27861820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2890 (or 2888 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 27861820 is about 5278.4296907319. The cubic root of 27861820 is about 303.1585543328.

It can be divided in two parts, 2786 and 1820, that multiplied together give a triangular number (5070520 = T₃₁₈₄).

The spelling of 27861820 in words is "twenty-seven million, eight hundred sixty-one thousand, eight hundred twenty".