81875555 has 12 divisors (see below), whose sum is σ = 101760672. Its totient is φ = 63238560.

The previous prime is 81875543. The next prime is 81875597. The reversal of 81875555 is 55557818.

It is not a de Polignac number, because 81875555 - 2⁶ = 81875491 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5531 + ... + 13940.

It is an arithmetic number, because the mean of its divisors is an integer number (8480056).

Almost surely, 2^81875555 is an apocalyptic number.

81875555 is a deficient number, since it is larger than the sum of its proper divisors (19885117).

81875555 is a wasteful number, since it uses less digits than its factorization.

81875555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19534 (or 19505 counting only the distinct ones).

The product of its digits is 280000, while the sum is 44.

The square root of 81875555 is about 9048.5112035075. The cubic root of 81875555 is about 434.2282612884.

The spelling of 81875555 in words is "eighty-one million, eight hundred seventy-five thousand, five hundred fifty-five".