42840997 has 2 divisors, whose sum is σ = 42840998. Its totient is φ = 42840996.

The previous prime is 42840949. The next prime is 42841009. The reversal of 42840997 is 79904824.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35034561 + 7806436 = 5919^2 + 2794^2 .

It is a cyclic number.

It is not a de Polignac number, because 42840997 - 2¹⁵ = 42808229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42840937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21420498 + 21420499.

It is an arithmetic number, because the mean of its divisors is an integer number (21420499).

Almost surely, 2^42840997 is an apocalyptic number.

It is an amenable number.

42840997 is a deficient number, since it is larger than the sum of its proper divisors (1).

42840997 is an equidigital number, since it uses as much as digits as its factorization.

42840997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 43.

The square root of 42840997 is about 6545.3034307051. The cubic root of 42840997 is about 349.9074503594.

The spelling of 42840997 in words is "forty-two million, eight hundred forty thousand, nine hundred ninety-seven".