20531611 has 8 divisors (see below), whose sum is σ = 21092400. Its totient is φ = 19973760.

The previous prime is 20531603. The next prime is 20531657. The reversal of 20531611 is 11613502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20531611 - 2³ = 20531603 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20538611) 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 7 ways as a sum of consecutive naturals, for example, 24975 + ... + 25783.

It is an arithmetic number, because the mean of its divisors is an integer number (2636550).

Almost surely, 2^20531611 is an apocalyptic number.

20531611 is a deficient number, since it is larger than the sum of its proper divisors (560789).

20531611 is an equidigital number, since it uses as much as digits as its factorization.

20531611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1469.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 20531611 is about 4531.1820753530. The cubic root of 20531611 is about 273.8257856797.

The spelling of 20531611 in words is "twenty million, five hundred thirty-one thousand, six hundred eleven".