81210971 has 8 divisors (see below), whose sum is σ = 83495424. Its totient is φ = 78949800.

The previous prime is 81210923. The next prime is 81210977. The reversal of 81210971 is 17901218.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81210971 - 2¹⁸ = 80948827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81210977) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1376 + ... + 12818.

It is an arithmetic number, because the mean of its divisors is an integer number (10436928).

Almost surely, 2^81210971 is an apocalyptic number.

81210971 is a deficient number, since it is larger than the sum of its proper divisors (2284453).

81210971 is a wasteful number, since it uses less digits than its factorization.

81210971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11641.

The product of its (nonzero) digits is 1008, while the sum is 29.

The square root of 81210971 is about 9011.7129892158. The cubic root of 81210971 is about 433.0501909046.

The spelling of 81210971 in words is "eighty-one million, two hundred ten thousand, nine hundred seventy-one".