20435531 has 2 divisors, whose sum is σ = 20435532. Its totient is φ = 20435530.

The previous prime is 20435501. The next prime is 20435533. The reversal of 20435531 is 13553402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20435531 - 2¹⁰ = 20434507 is a prime.

It is a super-2 number, since 2×20435531² = 835221854503922, which contains 22 as substring.

Together with 20435533, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20435497 and 20435506.

It is not a weakly prime, because it can be changed into another prime (20435533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10217765 + 10217766.

It is an arithmetic number, because the mean of its divisors is an integer number (10217766).

Almost surely, 2^20435531 is an apocalyptic number.

20435531 is a deficient number, since it is larger than the sum of its proper divisors (1).

20435531 is an equidigital number, since it uses as much as digits as its factorization.

20435531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1800, while the sum is 23.

The square root of 20435531 is about 4520.5675528632. The cubic root of 20435531 is about 273.3979847399.

Adding to 20435531 its reverse (13553402), we get a palindrome (33988933).

The spelling of 20435531 in words is "twenty million, four hundred thirty-five thousand, five hundred thirty-one".