81837828 has 18 divisors (see below), whose sum is σ = 206867934. Its totient is φ = 27279264.

The previous prime is 81837817. The next prime is 81837839. The reversal of 81837828 is 82873818.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81837817) and next prime (81837839).

It can be written as a sum of positive squares in only one way, i.e., 79174404 + 2663424 = 8898^2 + 1632^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1136601 + ... + 1136672.

It is an arithmetic number, because the mean of its divisors is an integer number (11492663).

Almost surely, 2^81837828 is an apocalyptic number.

It is an amenable number.

81837828 is an abundant number, since it is smaller than the sum of its proper divisors (125030106).

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

81837828 is a wasteful number, since it uses less digits than its factorization.

81837828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2273283 (or 2273278 counting only the distinct ones).

The product of its digits is 172032, while the sum is 45.

The square root of 81837828 is about 9046.4262557100. The cubic root of 81837828 is about 434.1615558008.

The spelling of 81837828 in words is "eighty-one million, eight hundred thirty-seven thousand, eight hundred twenty-eight".