81397302971 has 4 divisors (see below), whose sum is σ = 81397888200. Its totient is φ = 81396717744.

The previous prime is 81397302949. The next prime is 81397303003. The reversal of 81397302971 is 17920379318.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81397302971 is a prime.

It is a super-3 number, since 3×81397302971³ (a number of 34 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81397392971) 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, 48800 + ... + 406418.

It is an arithmetic number, because the mean of its divisors is an integer number (20349472050).

Almost surely, 2^81397302971 is an apocalyptic number.

81397302971 is a deficient number, since it is larger than the sum of its proper divisors (585229).

81397302971 is a wasteful number, since it uses less digits than its factorization.

81397302971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 585228.

The product of its (nonzero) digits is 571536, while the sum is 50.

The spelling of 81397302971 in words is "eighty-one billion, three hundred ninety-seven million, three hundred two thousand, nine hundred seventy-one".