87191807 has 2 divisors, whose sum is σ = 87191808. Its totient is φ = 87191806.

The previous prime is 87191791. The next prime is 87191821. The reversal of 87191807 is 70819178.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 87191807 - 2⁴ = 87191791 is a prime.

It is a super-2 number, since 2×87191807² = 15204822415850498, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87191887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43595903 + 43595904.

It is an arithmetic number, because the mean of its divisors is an integer number (43595904).

Almost surely, 2^87191807 is an apocalyptic number.

87191807 is a deficient number, since it is larger than the sum of its proper divisors (1).

87191807 is an equidigital number, since it uses as much as digits as its factorization.

87191807 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 41.

The square root of 87191807 is about 9337.6553266867. The cubic root of 87191807 is about 443.4301576197.

The spelling of 87191807 in words is "eighty-seven million, one hundred ninety-one thousand, eight hundred seven".