87811791 has 8 divisors (see below), whose sum is σ = 119938224. Its totient is φ = 57113280.

The previous prime is 87811781. The next prime is 87811793. The reversal of 87811791 is 19711878.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 87811791 - 2⁶ = 87811727 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87811793) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 356836 + ... + 357081.

It is an arithmetic number, because the mean of its divisors is an integer number (14992278).

Almost surely, 2^87811791 is an apocalyptic number.

87811791 is a deficient number, since it is larger than the sum of its proper divisors (32126433).

87811791 is a wasteful number, since it uses less digits than its factorization.

87811791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 713961.

The product of its digits is 28224, while the sum is 42.

The square root of 87811791 is about 9370.7945767688. The cubic root of 87811791 is about 444.4786909699.

The spelling of 87811791 in words is "eighty-seven million, eight hundred eleven thousand, seven hundred ninety-one".