81367137747 has 24 divisors (see below), whose sum is σ = 137950638176. Its totient is φ = 45238870656.

The previous prime is 81367137721. The next prime is 81367137769. The reversal of 81367137747 is 74773176318.

81367137747 is a `hidden beast` number, since 81 + 367 + 137 + 74 + 7 = 666.

It is not a de Polignac number, because 81367137747 - 2¹⁰ = 81367136723 is a prime.

It is a super-2 number, since 2×81367137747² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81367137693 and 81367137702.

It is not an unprimeable number, because it can be changed into a prime (81367137707) 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, 17450938 + ... + 17455599.

Almost surely, 2^81367137747 is an apocalyptic number.

81367137747 is a deficient number, since it is larger than the sum of its proper divisors (56583500429).

81367137747 is a wasteful number, since it uses less digits than its factorization.

81367137747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34906587 (or 34906584 counting only the distinct ones).

The product of its digits is 4148928, while the sum is 54.

The spelling of 81367137747 in words is "eighty-one billion, three hundred sixty-seven million, one hundred thirty-seven thousand, seven hundred forty-seven".