81444670 has 8 divisors (see below), whose sum is σ = 146600424. Its totient is φ = 32577864.

The previous prime is 81444653. The next prime is 81444707. The reversal of 81444670 is 7644418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4072224 + ... + 4072243.

It is an arithmetic number, because the mean of its divisors is an integer number (18325053).

Almost surely, 2^81444670 is an apocalyptic number.

81444670 is a deficient number, since it is larger than the sum of its proper divisors (65155754).

81444670 is a wasteful number, since it uses less digits than its factorization.

81444670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8144474.

The product of its (nonzero) digits is 21504, while the sum is 34.

The square root of 81444670 is about 9024.6700770721. The cubic root of 81444670 is about 433.4651860434.

The spelling of 81444670 in words is "eighty-one million, four hundred forty-four thousand, six hundred seventy".