42391491 has 4 divisors (see below), whose sum is σ = 56521992. Its totient is φ = 28260992.

The previous prime is 42391471. The next prime is 42391513. The reversal of 42391491 is 19419324.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 42391491 - 2¹⁴ = 42375107 is a prime.

It is not an unprimeable number, because it can be changed into a prime (42391411) 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, 7065246 + ... + 7065251.

It is an arithmetic number, because the mean of its divisors is an integer number (14130498).

Almost surely, 2^42391491 is an apocalyptic number.

42391491 is a deficient number, since it is larger than the sum of its proper divisors (14130501).

42391491 is a wasteful number, since it uses less digits than its factorization.

42391491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14130500.

The product of its digits is 7776, while the sum is 33.

The square root of 42391491 is about 6510.8748260122. The cubic root of 42391491 is about 348.6793523473.

The spelling of 42391491 in words is "forty-two million, three hundred ninety-one thousand, four hundred ninety-one".