20531697 has 4 divisors (see below), whose sum is σ = 27375600. Its totient is φ = 13687796.

The previous prime is 20531689. The next prime is 20531701. The reversal of 20531697 is 79613502.

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 a cyclic number.

It is not a de Polignac number, because 20531697 - 2³ = 20531689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20531657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3421947 + ... + 3421952.

It is an arithmetic number, because the mean of its divisors is an integer number (6843900).

Almost surely, 2^20531697 is an apocalyptic number.

It is an amenable number.

20531697 is a deficient number, since it is larger than the sum of its proper divisors (6843903).

20531697 is an equidigital number, since it uses as much as digits as its factorization.

20531697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6843902.

The product of its (nonzero) digits is 11340, while the sum is 33.

The square root of 20531697 is about 4531.1915651405. The cubic root of 20531697 is about 273.8261680005.

The spelling of 20531697 in words is "twenty million, five hundred thirty-one thousand, six hundred ninety-seven".