81037670047 has 4 divisors (see below), whose sum is σ = 81385471440. Its totient is φ = 80689868656.

The previous prime is 81037670041. The next prime is 81037670081. The reversal of 81037670047 is 74007673018.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74007673018 = 2 ⋅37003836509.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81037670047 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81037669985 and 81037670012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81037670041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 173900347 + ... + 173900812.

It is an arithmetic number, because the mean of its divisors is an integer number (20346367860).

Almost surely, 2^81037670047 is an apocalyptic number.

81037670047 is a deficient number, since it is larger than the sum of its proper divisors (347801393).

81037670047 is a wasteful number, since it uses less digits than its factorization.

81037670047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347801392.

The product of its (nonzero) digits is 197568, while the sum is 43.

The spelling of 81037670047 in words is "eighty-one billion, thirty-seven million, six hundred seventy thousand, forty-seven".