87191806 has 32 divisors (see below), whose sum is σ = 146694240. Its totient is φ = 38591616.

The previous prime is 87191791. The next prime is 87191807. The reversal of 87191806 is 60819178.

It is a super-2 number, since 2×87191806² = 15204822067083272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87191807) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 148245 + ... + 148831.

It is an arithmetic number, because the mean of its divisors is an integer number (4584195).

Almost surely, 2^87191806 is an apocalyptic number.

87191806 is a deficient number, since it is larger than the sum of its proper divisors (59502434).

87191806 is a wasteful number, since it uses less digits than its factorization.

87191806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 828.

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 87191806 is about 9337.6552731400. The cubic root of 87191806 is about 443.4301559245.

The spelling of 87191806 in words is "eighty-seven million, one hundred ninety-one thousand, eight hundred six".