20434421291 has 4 divisors (see below), whose sum is σ = 20436460800. Its totient is φ = 20432381784.

The previous prime is 20434421269. The next prime is 20434421417. The reversal of 20434421291 is 19212443402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19212443402 = 2 ⋅9606221701.

It is a cyclic number.

It is not a de Polignac number, because 20434421291 - 2³⁴ = 3254552107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20434421251) 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, 1004651 + ... + 1024788.

It is an arithmetic number, because the mean of its divisors is an integer number (5109115200).

Almost surely, 2^20434421291 is an apocalyptic number.

20434421291 is a deficient number, since it is larger than the sum of its proper divisors (2039509).

20434421291 is a wasteful number, since it uses less digits than its factorization.

20434421291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2039508.

The product of its (nonzero) digits is 13824, while the sum is 32.

Adding to 20434421291 its reverse (19212443402), we get a palindrome (39646864693).

The spelling of 20434421291 in words is "twenty billion, four hundred thirty-four million, four hundred twenty-one thousand, two hundred ninety-one".