81007635 has 32 divisors (see below), whose sum is σ = 137728512. Its totient is φ = 40517120.

The previous prime is 81007631. The next prime is 81007673. The reversal of 81007635 is 53670018.

It is not a de Polignac number, because 81007635 - 2² = 81007631 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81007631) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 124882 + ... + 125528.

It is an arithmetic number, because the mean of its divisors is an integer number (4304016).

Almost surely, 2^81007635 is an apocalyptic number.

81007635 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

81007635 is a deficient number, since it is larger than the sum of its proper divisors (56720877).

81007635 is a wasteful number, since it uses less digits than its factorization.

81007635 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1163.

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 81007635 is about 9000.4241566717. The cubic root of 81007635 is about 432.6884652027.

The spelling of 81007635 in words is "eighty-one million, seven thousand, six hundred thirty-five".