20434523 has 4 divisors (see below), whose sum is σ = 20932968. Its totient is φ = 19936080.

The previous prime is 20434507. The next prime is 20434537. The reversal of 20434523 is 32543402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32543402 = 2 ⋅16271701.

It is a cyclic number.

It is not a de Polignac number, because 20434523 - 2⁴ = 20434507 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20434553) 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, 249161 + ... + 249242.

It is an arithmetic number, because the mean of its divisors is an integer number (5233242).

Almost surely, 2^20434523 is an apocalyptic number.

20434523 is a deficient number, since it is larger than the sum of its proper divisors (498445).

20434523 is an equidigital number, since it uses as much as digits as its factorization.

20434523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498444.

The product of its (nonzero) digits is 2880, while the sum is 23.

The square root of 20434523 is about 4520.4560610629. The cubic root of 20434523 is about 273.3934894697.

Adding to 20434523 its reverse (32543402), we get a palindrome (52977925).

The spelling of 20434523 in words is "twenty million, four hundred thirty-four thousand, five hundred twenty-three".