81422971 has 4 divisors (see below), whose sum is σ = 93054832. Its totient is φ = 69791112.

The previous prime is 81422963. The next prime is 81422989. The reversal of 81422971 is 17922418.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17922418 = 2 ⋅8961209.

It is a cyclic number.

It is not a de Polignac number, because 81422971 - 2³ = 81422963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81422171) 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, 5815920 + ... + 5815933.

It is an arithmetic number, because the mean of its divisors is an integer number (23263708).

Almost surely, 2^81422971 is an apocalyptic number.

81422971 is a deficient number, since it is larger than the sum of its proper divisors (11631861).

81422971 is a wasteful number, since it uses less digits than its factorization.

81422971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11631860.

The product of its digits is 8064, while the sum is 34.

The square root of 81422971 is about 9023.4677923734. The cubic root of 81422971 is about 433.4266871193.

The spelling of 81422971 in words is "eighty-one million, four hundred twenty-two thousand, nine hundred seventy-one".