81026644 has 24 divisors (see below), whose sum is σ = 144387936. Its totient is φ = 39780000.

The previous prime is 81026629. The next prime is 81026681. The reversal of 81026644 is 44662018.

It is a congruent number.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 52159 + ... + 53689.

It is an arithmetic number, because the mean of its divisors is an integer number (6016164).

Almost surely, 2^81026644 is an apocalyptic number.

It is an amenable number.

81026644 is a deficient number, since it is larger than the sum of its proper divisors (63361292).

81026644 is a wasteful number, since it uses less digits than its factorization.

81026644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1767 (or 1765 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 81026644 is about 9001.4801005168. The cubic root of 81026644 is about 432.7223069995.

The spelling of 81026644 in words is "eighty-one million, twenty-six thousand, six hundred forty-four".