81682947 has 24 divisors (see below), whose sum is σ = 121631328. Its totient is φ = 52790400.

The previous prime is 81682927. The next prime is 81682961. The reversal of 81682947 is 74928618.

It is not a de Polignac number, because 81682947 - 2⁷ = 81682819 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81682927) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 66178 + ... + 67400.

It is an arithmetic number, because the mean of its divisors is an integer number (5067972).

Almost surely, 2^81682947 is an apocalyptic number.

81682947 is a deficient number, since it is larger than the sum of its proper divisors (39948381).

81682947 is a wasteful number, since it uses less digits than its factorization.

81682947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1451 (or 1448 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 81682947 is about 9037.8618599755. The cubic root of 81682947 is about 433.8874941091.

The spelling of 81682947 in words is "eighty-one million, six hundred eighty-two thousand, nine hundred forty-seven".