20434551 has 4 divisors (see below), whose sum is σ = 27246072. Its totient is φ = 13623032.

The previous prime is 20434537. The next prime is 20434553. The reversal of 20434551 is 15543402.

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 20434551 - 2¹⁵ = 20401783 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20434553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3405756 + ... + 3405761.

It is an arithmetic number, because the mean of its divisors is an integer number (6811518).

Almost surely, 2^20434551 is an apocalyptic number.

20434551 is a deficient number, since it is larger than the sum of its proper divisors (6811521).

20434551 is an equidigital number, since it uses as much as digits as its factorization.

20434551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6811520.

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 20434551 is about 4520.4591580945. The cubic root of 20434551 is about 273.3936143403.

Adding to 20434551 its reverse (15543402), we get a palindrome (35977953).

The spelling of 20434551 in words is "twenty million, four hundred thirty-four thousand, five hundred fifty-one".