81534951 has 16 divisors (see below), whose sum is σ = 121413600. Its totient is φ = 54077184.

The previous prime is 81534949. The next prime is 81534953. The reversal of 81534951 is 15943518.

It is an interprime number because it is at equal distance from previous prime (81534949) and next prime (81534953).

It is not a de Polignac number, because 81534951 - 2¹ = 81534949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81534953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2346 + ... + 12983.

It is an arithmetic number, because the mean of its divisors is an integer number (7588350).

Almost surely, 2^81534951 is an apocalyptic number.

81534951 is a deficient number, since it is larger than the sum of its proper divisors (39878649).

81534951 is a wasteful number, since it uses less digits than its factorization.

81534951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15535 (or 15529 counting only the distinct ones).

The product of its digits is 21600, while the sum is 36.

The square root of 81534951 is about 9029.6705919984. The cubic root of 81534951 is about 433.6252915462.

The spelling of 81534951 in words is "eighty-one million, five hundred thirty-four thousand, nine hundred fifty-one".