42415991 has 4 divisors (see below), whose sum is σ = 42429984. Its totient is φ = 42402000.

The previous prime is 42415981. The next prime is 42416027. The reversal of 42415991 is 19951424.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 42415991 - 2⁶ = 42415927 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 (42415981) 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, 335 + ... + 9216.

It is an arithmetic number, because the mean of its divisors is an integer number (10607496).

Almost surely, 2^42415991 is an apocalyptic number.

42415991 is a deficient number, since it is larger than the sum of its proper divisors (13993).

42415991 is an equidigital number, since it uses as much as digits as its factorization.

42415991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13992.

The product of its digits is 12960, while the sum is 35.

The square root of 42415991 is about 6512.7560218390. The cubic root of 42415991 is about 348.7465120432.

The spelling of 42415991 in words is "forty-two million, four hundred fifteen thousand, nine hundred ninety-one".