87261209 has 12 divisors (see below), whose sum is σ = 101783988. Its totient is φ = 74592000.

The previous prime is 87261193. The next prime is 87261211. The reversal of 87261209 is 90216278.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 67190809 + 20070400 = 8197^2 + 4480^2 .

It is not a de Polignac number, because 87261209 - 2⁴ = 87261193 is a prime.

It is a super-2 number, since 2×87261209² = 15229037192283362, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (87261299) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17429 + ... + 21869.

It is an arithmetic number, because the mean of its divisors is an integer number (8481999).

Almost surely, 2^87261209 is an apocalyptic number.

It is an amenable number.

87261209 is a deficient number, since it is larger than the sum of its proper divisors (14522779).

87261209 is a wasteful number, since it uses less digits than its factorization.

87261209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4856 (or 4849 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 87261209 is about 9341.3708308792. The cubic root of 87261209 is about 443.5477786790.

The spelling of 87261209 in words is "eighty-seven million, two hundred sixty-one thousand, two hundred nine".