81491136006 has 16 divisors (see below), whose sum is σ = 186265453824. Its totient is φ = 23283181704.

The previous prime is 81491135989. The next prime is 81491136007. The reversal of 81491136006 is 60063119418.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81491136007) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 970132530 + ... + 970132613.

It is an arithmetic number, because the mean of its divisors is an integer number (11641590864).

Almost surely, 2^81491136006 is an apocalyptic number.

81491136006 is an abundant number, since it is smaller than the sum of its proper divisors (104774317818).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81491136006 is a wasteful number, since it uses less digits than its factorization.

81491136006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1940265155.

The product of its (nonzero) digits is 31104, while the sum is 39.

The spelling of 81491136006 in words is "eighty-one billion, four hundred ninety-one million, one hundred thirty-six thousand, six".