20735531 has 4 divisors (see below), whose sum is σ = 20816472. Its totient is φ = 20654592.

The previous prime is 20735521. The next prime is 20735537. The reversal of 20735531 is 13553702.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20735531 - 2⁶ = 20735467 is a prime.

It is a super-2 number, since 2×20735531² = 859924491703922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20735531.

It is not an unprimeable number, because it can be changed into a prime (20735537) 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, 40085 + ... + 40598.

It is an arithmetic number, because the mean of its divisors is an integer number (5204118).

Almost surely, 2^20735531 is an apocalyptic number.

20735531 is a deficient number, since it is larger than the sum of its proper divisors (80941).

20735531 is an equidigital number, since it uses as much as digits as its factorization.

20735531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80940.

The product of its (nonzero) digits is 3150, while the sum is 26.

The square root of 20735531 is about 4553.6283335380. The cubic root of 20735531 is about 274.7293469357.

The spelling of 20735531 in words is "twenty million, seven hundred thirty-five thousand, five hundred thirty-one".