81553792 has 16 divisors (see below), whose sum is σ = 162470700. Its totient is φ = 40776832.

The previous prime is 81553783. The next prime is 81553799. The reversal of 81553792 is 29735518.

It is a tau number, because it is divible by the number of its divisors (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81553799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318442 + ... + 318697.

Almost surely, 2^81553792 is an apocalyptic number.

It is an amenable number.

81553792 is a deficient number, since it is larger than the sum of its proper divisors (80916908).

81553792 is an equidigital number, since it uses as much as digits as its factorization.

81553792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 637153 (or 637141 counting only the distinct ones).

The product of its digits is 75600, while the sum is 40.

The square root of 81553792 is about 9030.7138145332. The cubic root of 81553792 is about 433.6586895136.

The spelling of 81553792 in words is "eighty-one million, five hundred fifty-three thousand, seven hundred ninety-two".