81630376 has 8 divisors (see below), whose sum is σ = 153056970. Its totient is φ = 40815184.

The previous prime is 81630371. The next prime is 81630401. The reversal of 81630376 is 67303618.

It can be written as a sum of positive squares in only one way, i.e., 44542276 + 37088100 = 6674^2 + 6090^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (81630371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5101891 + ... + 5101906.

Almost surely, 2^81630376 is an apocalyptic number.

It is an amenable number.

81630376 is a deficient number, since it is larger than the sum of its proper divisors (71426594).

81630376 is a wasteful number, since it uses less digits than its factorization.

81630376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10203803 (or 10203799 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 81630376 is about 9034.9530159265. The cubic root of 81630376 is about 433.7943910584.

The spelling of 81630376 in words is "eighty-one million, six hundred thirty thousand, three hundred seventy-six".