42987431 has 2 divisors, whose sum is σ = 42987432. Its totient is φ = 42987430.

The previous prime is 42987403. The next prime is 42987433. The reversal of 42987431 is 13478924.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 42987431 - 2¹⁰ = 42986407 is a prime.

It is a super-2 number, since 2×42987431² = 3695838447959522, which contains 22 as substring.

Together with 42987433, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42987433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21493715 + 21493716.

It is an arithmetic number, because the mean of its divisors is an integer number (21493716).

Almost surely, 2^42987431 is an apocalyptic number.

42987431 is a deficient number, since it is larger than the sum of its proper divisors (1).

42987431 is an equidigital number, since it uses as much as digits as its factorization.

42987431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48384, while the sum is 38.

The square root of 42987431 is about 6556.4800769925. The cubic root of 42987431 is about 350.3056676655.

The spelling of 42987431 in words is "forty-two million, nine hundred eighty-seven thousand, four hundred thirty-one".