42540551 has 2 divisors, whose sum is σ = 42540552. Its totient is φ = 42540550.

The previous prime is 42540541. The next prime is 42540557. The reversal of 42540551 is 15504524.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 42540551 - 2¹⁰ = 42539527 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 42540551.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42540557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21270275 + 21270276.

It is an arithmetic number, because the mean of its divisors is an integer number (21270276).

Almost surely, 2^42540551 is an apocalyptic number.

42540551 is a deficient number, since it is larger than the sum of its proper divisors (1).

42540551 is an equidigital number, since it uses as much as digits as its factorization.

42540551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4000, while the sum is 26.

The square root of 42540551 is about 6522.3117834093. The cubic root of 42540551 is about 349.0875580458.

The spelling of 42540551 in words is "forty-two million, five hundred forty thousand, five hundred fifty-one".