81189662446 has 8 divisors (see below), whose sum is σ = 121789732824. Its totient is φ = 40593084840.

The previous prime is 81189662311. The next prime is 81189662467. The reversal of 81189662446 is 64426698118.

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

It is a super-2 number, since 2×81189662446² (a number of 23 digits) contains 22 as substring.

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, 814285 + ... + 908536.

It is an arithmetic number, because the mean of its divisors is an integer number (15223716603).

Almost surely, 2^81189662446 is an apocalyptic number.

81189662446 is a deficient number, since it is larger than the sum of its proper divisors (40600070378).

81189662446 is a wasteful number, since it uses less digits than its factorization.

81189662446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1746386.

The product of its digits is 3981312, while the sum is 55.

The spelling of 81189662446 in words is "eighty-one billion, one hundred eighty-nine million, six hundred sixty-two thousand, four hundred forty-six".