2137521 has 4 divisors (see below), whose sum is σ = 2850032. Its totient is φ = 1425012.

The previous prime is 2137517. The next prime is 2137547. The reversal of 2137521 is 1257312.

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 not a de Polignac number, because 2137521 - 2² = 2137517 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2137571) 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, 356251 + ... + 356256.

It is an arithmetic number, because the mean of its divisors is an integer number (712508).

2^2137521 is an apocalyptic number.

It is an amenable number.

2137521 is a deficient number, since it is larger than the sum of its proper divisors (712511).

2137521 is an equidigital number, since it uses as much as digits as its factorization.

2137521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 712510.

The product of its digits is 420, while the sum is 21.

The square root of 2137521 is about 1462.0263335522. The cubic root of 2137521 is about 128.8160951364.

The spelling of 2137521 in words is "two million, one hundred thirty-seven thousand, five hundred twenty-one".