42431220 has 72 divisors (see below), whose sum is σ = 138616296. Its totient is φ = 10444032.

The previous prime is 42431209. The next prime is 42431227. The reversal of 42431220 is 2213424.

It can be written as a sum of positive squares in 4 ways, for example, as 285156 + 42146064 = 534^2 + 6492^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 42431193 and 42431202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42431227) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6727 + ... + 11406.

Almost surely, 2^42431220 is an apocalyptic number.

It is an amenable number.

42431220 is an abundant number, since it is smaller than the sum of its proper divisors (96185076).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

42431220 is a wasteful number, since it uses less digits than its factorization.

42431220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18161 (or 18156 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 42431220 is about 6513.9250840027. The cubic root of 42431220 is about 348.7882449290.

Adding to 42431220 its reverse (2213424), we get a palindrome (44644644).

The spelling of 42431220 in words is "forty-two million, four hundred thirty-one thousand, two hundred twenty".