81576648 has 24 divisors (see below), whose sum is σ = 220936950. Its totient is φ = 27192192.

The previous prime is 81576643. The next prime is 81576689. The reversal of 81576648 is 84667518.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 48191364 + 33385284 = 6942^2 + 5778^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is not an unprimeable number, because it can be changed into a prime (81576643) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 566433 + ... + 566576.

Almost surely, 2^81576648 is an apocalyptic number.

It is an amenable number.

81576648 is an abundant number, since it is smaller than the sum of its proper divisors (139360302).

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

81576648 is a wasteful number, since it uses less digits than its factorization.

81576648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1133021 (or 1133014 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The square root of 81576648 is about 9031.9791850956. The cubic root of 81576648 is about 433.6991976534.

The spelling of 81576648 in words is "eighty-one million, five hundred seventy-six thousand, six hundred forty-eight".