81954971 has 8 divisors (see below), whose sum is σ = 94187520. Its totient is φ = 69853608.

The previous prime is 81954959. The next prime is 81954973. The reversal of 81954971 is 17945918.

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 81954971 - 2¹⁸ = 81692827 is a prime.

It is a super-2 number, since 2×81954971² = 13433234543221682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81954973) 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, 31451 + ... + 33956.

It is an arithmetic number, because the mean of its divisors is an integer number (11773440).

Almost surely, 2^81954971 is an apocalyptic number.

81954971 is a deficient number, since it is larger than the sum of its proper divisors (12232549).

81954971 is a wasteful number, since it uses less digits than its factorization.

81954971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65593.

The product of its digits is 90720, while the sum is 44.

The square root of 81954971 is about 9052.8984861203. The cubic root of 81954971 is about 434.3686105783.

The spelling of 81954971 in words is "eighty-one million, nine hundred fifty-four thousand, nine hundred seventy-one".