87391789 has 4 divisors (see below), whose sum is σ = 91191456. Its totient is φ = 83592124.

The previous prime is 87391771. The next prime is 87391813. The reversal of 87391789 is 98719378.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 87391789 - 2⁵ = 87391757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87391709) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1899799 + ... + 1899844.

It is an arithmetic number, because the mean of its divisors is an integer number (22797864).

Almost surely, 2^87391789 is an apocalyptic number.

It is an amenable number.

87391789 is a deficient number, since it is larger than the sum of its proper divisors (3799667).

87391789 is a wasteful number, since it uses less digits than its factorization.

87391789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3799666.

The product of its digits is 762048, while the sum is 52.

The square root of 87391789 is about 9348.3575562769. The cubic root of 87391789 is about 443.7689139859.

It can be divided in two parts, 87 and 391789, that added together give a square (391876 = 626²).

The spelling of 87391789 in words is "eighty-seven million, three hundred ninety-one thousand, seven hundred eighty-nine".