81862320 has 80 divisors (see below), whose sum is σ = 261983232. Its totient is φ = 21123840.

The previous prime is 81862283. The next prime is 81862321. The reversal of 81862320 is 2326818.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (81862321) 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, 1939 + ... + 12941.

Almost surely, 2^81862320 is an apocalyptic number.

81862320 is a gapful number since it is divisible by the number (80) 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 81862320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130991616).

81862320 is an abundant number, since it is smaller than the sum of its proper divisors (180120912).

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

81862320 is a wasteful number, since it uses less digits than its factorization.

81862320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11050 (or 11044 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 81862320 is about 9047.7798381702. The cubic root of 81862320 is about 434.2048626858.

The spelling of 81862320 in words is "eighty-one million, eight hundred sixty-two thousand, three hundred twenty".