42389991 has 24 divisors (see below), whose sum is σ = 70630560. Its totient is φ = 23996736.

The previous prime is 42389957. The next prime is 42389999. The reversal of 42389991 is 19998324.

It is not a de Polignac number, because 42389991 - 2⁷ = 42389863 is a prime.

It is a super-2 number, since 2×42389991² = 3593822673960162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42389999) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3781 + ... + 9953.

It is an arithmetic number, because the mean of its divisors is an integer number (2942940).

Almost surely, 2^42389991 is an apocalyptic number.

42389991 is a deficient number, since it is larger than the sum of its proper divisors (28240569).

42389991 is a wasteful number, since it uses less digits than its factorization.

42389991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6295 (or 6292 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 42389991 is about 6510.7596330997. The cubic root of 42389991 is about 348.6752396886.

The spelling of 42389991 in words is "forty-two million, three hundred eighty-nine thousand, nine hundred ninety-one".