100871581 has 4 divisors (see below), whose sum is σ = 100950652. Its totient is φ = 100792512.

The previous prime is 100871567. The next prime is 100871611. The reversal of 100871581 is 185178001.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 64160100 + 36711481 = 8010^2 + 6059^2 .

It is a cyclic number.

It is not a de Polignac number, because 100871581 - 2⁵ = 100871549 is a prime.

It is a super-2 number, since 2×100871581² = 20350151706879122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100874581) 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, 37590 + ... + 40183.

It is an arithmetic number, because the mean of its divisors is an integer number (25237663).

Almost surely, 2^100871581 is an apocalyptic number.

It is an amenable number.

100871581 is a deficient number, since it is larger than the sum of its proper divisors (79071).

100871581 is an equidigital number, since it uses as much as digits as its factorization.

100871581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79070.

The product of its (nonzero) digits is 2240, while the sum is 31.

The square root of 100871581 is about 10043.4845048917. The cubic root of 100871581 is about 465.5034913246.

The spelling of 100871581 in words is "one hundred million, eight hundred seventy-one thousand, five hundred eighty-one".