81191948 has 12 divisors (see below), whose sum is σ = 142179240. Its totient is φ = 40569312.

The previous prime is 81191947. The next prime is 81191953. The reversal of 81191948 is 84919118.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (81191947) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1223 + ... + 12801.

It is an arithmetic number, because the mean of its divisors is an integer number (11848270).

Almost surely, 2^81191948 is an apocalyptic number.

It is an amenable number.

81191948 is a deficient number, since it is larger than the sum of its proper divisors (60987292).

81191948 is a wasteful number, since it uses less digits than its factorization.

81191948 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13336 (or 13334 counting only the distinct ones).

The product of its digits is 20736, while the sum is 41.

The square root of 81191948 is about 9010.6574676879. The cubic root of 81191948 is about 433.0163754525.

The spelling of 81191948 in words is "eighty-one million, one hundred ninety-one thousand, nine hundred forty-eight".