20525537 has 4 divisors (see below), whose sum is σ = 20562180. Its totient is φ = 20488896.

The previous prime is 20525521. The next prime is 20525539. The reversal of 20525537 is 73552502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 73552502 = 2 ⋅36776251.

It can be written as a sum of positive squares in 2 ways, for example, as 11621281 + 8904256 = 3409^2 + 2984^2 .

It is a cyclic number.

It is not a de Polignac number, because 20525537 - 2⁴ = 20525521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20525539) 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, 17468 + ... + 18605.

It is an arithmetic number, because the mean of its divisors is an integer number (5140545).

Almost surely, 2^20525537 is an apocalyptic number.

It is an amenable number.

20525537 is a deficient number, since it is larger than the sum of its proper divisors (36643).

20525537 is an equidigital number, since it uses as much as digits as its factorization.

20525537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36642.

The product of its (nonzero) digits is 10500, while the sum is 29.

The square root of 20525537 is about 4530.5117812450. The cubic root of 20525537 is about 273.7987804622.

The spelling of 20525537 in words is "twenty million, five hundred twenty-five thousand, five hundred thirty-seven".