81576630 has 48 divisors (see below), whose sum is σ = 221326560. Its totient is φ = 20807424.

The previous prime is 81576613. The next prime is 81576637. The reversal of 81576630 is 3667518.

81576630 is a `hidden beast` number, since 8 + 15 + 7 + 6 + 630 = 666.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81576637) 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, 17635 + ... + 21774.

It is an arithmetic number, because the mean of its divisors is an integer number (4610970).

Almost surely, 2^81576630 is an apocalyptic number.

81576630 is an abundant number, since it is smaller than the sum of its proper divisors (139749930).

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

81576630 is a wasteful number, since it uses less digits than its factorization.

81576630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39445 (or 39442 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 81576630 is about 9031.9781886362. The cubic root of 81576630 is about 433.6991657546.

The spelling of 81576630 in words is "eighty-one million, five hundred seventy-six thousand, six hundred thirty".