81324747 has 12 divisors (see below), whose sum is σ = 134250480. Its totient is φ = 46471248.

The previous prime is 81324721. The next prime is 81324751. The reversal of 81324747 is 74742318.

It is a happy number.

It is not a de Polignac number, because 81324747 - 2¹⁴ = 81308363 is a prime.

It is a super-2 number, since 2×81324747² = 13227428949228018, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81324767) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 645372 + ... + 645497.

It is an arithmetic number, because the mean of its divisors is an integer number (11187540).

Almost surely, 2^81324747 is an apocalyptic number.

81324747 is a deficient number, since it is larger than the sum of its proper divisors (52925733).

81324747 is a wasteful number, since it uses less digits than its factorization.

81324747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1290882 (or 1290879 counting only the distinct ones).

The product of its digits is 37632, while the sum is 36.

The square root of 81324747 is about 9018.0234530633. The cubic root of 81324747 is about 433.2523299608.

The spelling of 81324747 in words is "eighty-one million, three hundred twenty-four thousand, seven hundred forty-seven".