81954277 has 4 divisors (see below), whose sum is σ = 86267680. Its totient is φ = 77640876.

The previous prime is 81954269. The next prime is 81954287. The reversal of 81954277 is 77245918.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81954277 - 2³ = 81954269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81954227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2156673 + ... + 2156710.

It is an arithmetic number, because the mean of its divisors is an integer number (21566920).

Almost surely, 2^81954277 is an apocalyptic number.

It is an amenable number.

81954277 is a deficient number, since it is larger than the sum of its proper divisors (4313403).

81954277 is a wasteful number, since it uses less digits than its factorization.

81954277 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4313402.

The product of its digits is 141120, while the sum is 43.

The square root of 81954277 is about 9052.8601557740. The cubic root of 81954277 is about 434.3673844877.

The spelling of 81954277 in words is "eighty-one million, nine hundred fifty-four thousand, two hundred seventy-seven".