42400020431 has 2 divisors, whose sum is σ = 42400020432. Its totient is φ = 42400020430.

The previous prime is 42400020419. The next prime is 42400020451. The reversal of 42400020431 is 13402000424.

It is an a-pointer prime, because the next prime (42400020451) can be obtained adding 42400020431 to its sum of digits (20).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42400020431 is a prime.

It is a super-2 number, since 2×42400020431² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42400020451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21200010215 + 21200010216.

It is an arithmetic number, because the mean of its divisors is an integer number (21200010216).

Almost surely, 2^42400020431 is an apocalyptic number.

42400020431 is a deficient number, since it is larger than the sum of its proper divisors (1).

42400020431 is an equidigital number, since it uses as much as digits as its factorization.

42400020431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 20.

Adding to 42400020431 its reverse (13402000424), we get a palindrome (55802020855).

The spelling of 42400020431 in words is "forty-two billion, four hundred million, twenty thousand, four hundred thirty-one".