20430034021 has 4 divisors (see below), whose sum is σ = 20430352332. Its totient is φ = 20429715712.

The previous prime is 20430034013. The next prime is 20430034061. The reversal of 20430034021 is 12043003402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12043003402 = 2 ⋅6021501701.

It can be written as a sum of positive squares in 2 ways, for example, as 8129005921 + 12301028100 = 90161^2 + 110910^2 .

It is a cyclic number.

It is not a de Polignac number, because 20430034021 - 2³ = 20430034013 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20430034021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20430034061) 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, 25426 + ... + 203731.

It is an arithmetic number, because the mean of its divisors is an integer number (5107588083).

Almost surely, 2^20430034021 is an apocalyptic number.

It is an amenable number.

20430034021 is a deficient number, since it is larger than the sum of its proper divisors (318311).

20430034021 is an equidigital number, since it uses as much as digits as its factorization.

20430034021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318310.

The product of its (nonzero) digits is 576, while the sum is 19.

Adding to 20430034021 its reverse (12043003402), we get a palindrome (32473037423).

The spelling of 20430034021 in words is "twenty billion, four hundred thirty million, thirty-four thousand, twenty-one".