87156109 has 4 divisors (see below), whose sum is σ = 87927516. Its totient is φ = 86384704.

The previous prime is 87156103. The next prime is 87156137. The reversal of 87156109 is 90165178.

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 3433609 + 83722500 = 1853^2 + 9150^2 .

It is a cyclic number.

It is not a de Polignac number, because 87156109 - 2⁹ = 87155597 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 (87156103) 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, 385534 + ... + 385759.

It is an arithmetic number, because the mean of its divisors is an integer number (21981879).

Almost surely, 2^87156109 is an apocalyptic number.

It is an amenable number.

87156109 is a deficient number, since it is larger than the sum of its proper divisors (771407).

87156109 is a wasteful number, since it uses less digits than its factorization.

It is an anagram of its base 13 representation: 87156109 = (15097681)₁₃.

87156109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 771406.

The product of its (nonzero) digits is 15120, while the sum is 37.

The square root of 87156109 is about 9335.7436233007. The cubic root of 87156109 is about 443.3696330853.

The spelling of 87156109 in words is "eighty-seven million, one hundred fifty-six thousand, one hundred nine".