81371834475 has 24 divisors (see below), whose sum is σ = 136046404080. Its totient is φ = 42910686720.

The previous prime is 81371834473. The next prime is 81371834491. The reversal of 81371834475 is 57443817318.

It is not a de Polignac number, because 81371834475 - 2¹ = 81371834473 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81371834473) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6088594 + ... + 6101943.

It is an arithmetic number, because the mean of its divisors is an integer number (5668600170).

Almost surely, 2^81371834475 is an apocalyptic number.

81371834475 is a deficient number, since it is larger than the sum of its proper divisors (54674569605).

81371834475 is a wasteful number, since it uses less digits than its factorization.

81371834475 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12190639 (or 12190634 counting only the distinct ones).

The product of its digits is 2257920, while the sum is 51.

The spelling of 81371834475 in words is "eighty-one billion, three hundred seventy-one million, eight hundred thirty-four thousand, four hundred seventy-five".