20535531 has 4 divisors (see below), whose sum is σ = 27380712. Its totient is φ = 13690352.

The previous prime is 20535503. The next prime is 20535533. The reversal of 20535531 is 13553502.

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 20535531 - 2⁵ = 20535499 is a prime.

It is a super-2 number, since 2×20535531² = 843416066903922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20535533) 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, 3422586 + ... + 3422591.

It is an arithmetic number, because the mean of its divisors is an integer number (6845178).

Almost surely, 2^20535531 is an apocalyptic number.

20535531 is a deficient number, since it is larger than the sum of its proper divisors (6845181).

20535531 is an equidigital number, since it uses as much as digits as its factorization.

20535531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6845180.

The product of its (nonzero) digits is 2250, while the sum is 24.

The square root of 20535531 is about 4531.6146129167. The cubic root of 20535531 is about 273.8432113098.

The spelling of 20535531 in words is "twenty million, five hundred thirty-five thousand, five hundred thirty-one".