81553976 has 16 divisors (see below), whose sum is σ = 174758640. Its totient is φ = 34951680.

The previous prime is 81553973. The next prime is 81553987. The reversal of 81553976 is 67935518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81553973) 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, 728105 + ... + 728216.

It is an arithmetic number, because the mean of its divisors is an integer number (10922415).

Almost surely, 2^81553976 is an apocalyptic number.

It is an amenable number.

81553976 is an abundant number, since it is smaller than the sum of its proper divisors (93204664).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81553976 is a wasteful number, since it uses less digits than its factorization.

81553976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1456334 (or 1456330 counting only the distinct ones).

The product of its digits is 226800, while the sum is 44.

The square root of 81553976 is about 9030.7240019835. The cubic root of 81553976 is about 433.6590156506.

The spelling of 81553976 in words is "eighty-one million, five hundred fifty-three thousand, nine hundred seventy-six".