2187521 has 16 divisors (see below), whose sum is σ = 2618880. Its totient is φ = 1788480.

The previous prime is 2187517. The next prime is 2187529. The reversal of 2187521 is 1257812.

It is a cyclic number.

It is not a de Polignac number, because 2187521 - 2² = 2187517 is a prime.

It is a Duffinian number.

Its product of digits (1120) is a multiple of the sum of its prime divisors (224).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2187529) 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, 20015 + ... + 20123.

It is an arithmetic number, because the mean of its divisors is an integer number (163680).

2^2187521 is an apocalyptic number.

It is an amenable number.

2187521 is a deficient number, since it is larger than the sum of its proper divisors (431359).

2187521 is a wasteful number, since it uses less digits than its factorization.

2187521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224.

The product of its digits is 1120, while the sum is 26.

The square root of 2187521 is about 1479.0270450536. The cubic root of 2187521 is about 129.8127679445.

The spelling of 2187521 in words is "two million, one hundred eighty-seven thousand, five hundred twenty-one".