20420435431 has 4 divisors (see below), whose sum is σ = 22276838664. Its totient is φ = 18564032200.

The previous prime is 20420435393. The next prime is 20420435443. The reversal of 20420435431 is 13453402402.

It is a happy number.

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 20420435431 - 2¹³ = 20420427239 is a prime.

It is a super-2 number, since 2×20420435431² (a number of 21 digits) contains 22 as substring.

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 20420435431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20420435461) 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, 928201600 + ... + 928201621.

It is an arithmetic number, because the mean of its divisors is an integer number (5569209666).

Almost surely, 2^20420435431 is an apocalyptic number.

20420435431 is a deficient number, since it is larger than the sum of its proper divisors (1856403233).

20420435431 is a wasteful number, since it uses less digits than its factorization.

20420435431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1856403232.

The product of its (nonzero) digits is 11520, while the sum is 28.

Adding to 20420435431 its reverse (13453402402), we get a palindrome (33873837833).

The spelling of 20420435431 in words is "twenty billion, four hundred twenty million, four hundred thirty-five thousand, four hundred thirty-one".