42138997 has 4 divisors (see below), whose sum is σ = 42732576. Its totient is φ = 41545420.

The previous prime is 42138991. The next prime is 42139003. The reversal of 42138997 is 79983124.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (42138991) and next prime (42139003).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42138997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42138991) 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, 296683 + ... + 296824.

It is an arithmetic number, because the mean of its divisors is an integer number (10683144).

Almost surely, 2^42138997 is an apocalyptic number.

It is an amenable number.

42138997 is a deficient number, since it is larger than the sum of its proper divisors (593579).

42138997 is an equidigital number, since it uses as much as digits as its factorization.

42138997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 593578.

The product of its digits is 108864, while the sum is 43.

The square root of 42138997 is about 6491.4556919076. The cubic root of 42138997 is about 347.9857004077.

The spelling of 42138997 in words is "forty-two million, one hundred thirty-eight thousand, nine hundred ninety-seven".