81491136370 has 32 divisors (see below), whose sum is σ = 167817194496. Its totient is φ = 27910104000.

The previous prime is 81491136367. The next prime is 81491136469. The reversal of 81491136370 is 7363119418.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 552706 + ... + 684445.

It is an arithmetic number, because the mean of its divisors is an integer number (5244287328).

Almost surely, 2^81491136370 is an apocalyptic number.

81491136370 is an abundant number, since it is smaller than the sum of its proper divisors (86326058126).

81491136370 is a wasteful number, since it uses less digits than its factorization.

81491136370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1238106.

The product of its (nonzero) digits is 108864, while the sum is 43.

The spelling of 81491136370 in words is "eighty-one billion, four hundred ninety-one million, one hundred thirty-six thousand, three hundred seventy".