81308762 has 4 divisors (see below), whose sum is σ = 121963146. Its totient is φ = 40654380.

The previous prime is 81308761. The next prime is 81308783. The reversal of 81308762 is 26780318.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 80478841 + 829921 = 8971^2 + 911^2 .

It is a super-2 number, since 2×81308762² = 13222229555945288, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81308761) 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, 20327189 + ... + 20327192.

Almost surely, 2^81308762 is an apocalyptic number.

81308762 is a deficient number, since it is larger than the sum of its proper divisors (40654384).

81308762 is a wasteful number, since it uses less digits than its factorization.

81308762 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40654383.

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 81308762 is about 9017.1371288231. The cubic root of 81308762 is about 433.2239417495.

The spelling of 81308762 in words is "eighty-one million, three hundred eight thousand, seven hundred sixty-two".