42531421 has 4 divisors (see below), whose sum is σ = 42563772. Its totient is φ = 42499072.

The previous prime is 42531413. The next prime is 42531431. The reversal of 42531421 is 12413524.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 42380100 + 151321 = 6510^2 + 389^2 .

It is a cyclic number.

It is not a de Polignac number, because 42531421 - 2³ = 42531413 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42531392 and 42531401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42531431) 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, 14116 + ... + 16861.

It is an arithmetic number, because the mean of its divisors is an integer number (10640943).

Almost surely, 2^42531421 is an apocalyptic number.

It is an amenable number.

42531421 is a deficient number, since it is larger than the sum of its proper divisors (32351).

42531421 is a wasteful number, since it uses less digits than its factorization.

42531421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32350.

The product of its digits is 960, while the sum is 22.

The square root of 42531421 is about 6521.6118406419. The cubic root of 42531421 is about 349.0625826802.

Adding to 42531421 its reverse (12413524), we get a palindrome (54944945).

The spelling of 42531421 in words is "forty-two million, five hundred thirty-one thousand, four hundred twenty-one".