81849372 has 96 divisors (see below), whose sum is σ = 216760320. Its totient is φ = 23824320.

The previous prime is 81849367. The next prime is 81849377. The reversal of 81849372 is 27394818.

It is an interprime number because it is at equal distance from previous prime (81849367) and next prime (81849377).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81849377) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 490033 + ... + 490199.

It is an arithmetic number, because the mean of its divisors is an integer number (2257920).

Almost surely, 2^81849372 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81849372, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108380160).

81849372 is an abundant number, since it is smaller than the sum of its proper divisors (134910948).

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

81849372 is a wasteful number, since it uses less digits than its factorization.

81849372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311 (or 309 counting only the distinct ones).

The product of its digits is 96768, while the sum is 42.

The square root of 81849372 is about 9047.0642752221. The cubic root of 81849372 is about 434.1819690395.

The spelling of 81849372 in words is "eighty-one million, eight hundred forty-nine thousand, three hundred seventy-two".