87561547221 has 16 divisors (see below), whose sum is σ = 119297654784. Its totient is φ = 57101254704.

The previous prime is 87561547217. The next prime is 87561547231. The reversal of 87561547221 is 12274516578.

It is not a de Polignac number, because 87561547221 - 2² = 87561547217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87561547231) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 92316 + ... + 428538.

It is an arithmetic number, because the mean of its divisors is an integer number (7456103424).

Almost surely, 2^87561547221 is an apocalyptic number.

It is an amenable number.

87561547221 is a deficient number, since it is larger than the sum of its proper divisors (31736107563).

87561547221 is a wasteful number, since it uses less digits than its factorization.

87561547221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338120.

The product of its digits is 940800, while the sum is 48.

The spelling of 87561547221 in words is "eighty-seven billion, five hundred sixty-one million, five hundred forty-seven thousand, two hundred twenty-one".