81557052 has 12 divisors (see below), whose sum is σ = 190299816. Its totient is φ = 27185680.

The previous prime is 81557027. The next prime is 81557071. The reversal of 81557052 is 25075518.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3398199 + ... + 3398222.

It is an arithmetic number, because the mean of its divisors is an integer number (15858318).

Almost surely, 2^81557052 is an apocalyptic number.

It is an amenable number.

81557052 is an abundant number, since it is smaller than the sum of its proper divisors (108742764).

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

81557052 is a wasteful number, since it uses less digits than its factorization.

81557052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6796428 (or 6796426 counting only the distinct ones).

The product of its (nonzero) digits is 14000, while the sum is 33.

The square root of 81557052 is about 9030.8943078745. The cubic root of 81557052 is about 433.6644677386.

The spelling of 81557052 in words is "eighty-one million, five hundred fifty-seven thousand, fifty-two".