42129891 has 12 divisors (see below), whose sum is σ = 61004320. Its totient is φ = 28017360.

The previous prime is 42129877. The next prime is 42129911. The reversal of 42129891 is 19892124.

42129891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 42129891 - 2¹¹ = 42127843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42129811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1771 + ... + 9348.

Almost surely, 2^42129891 is an apocalyptic number.

42129891 is a deficient number, since it is larger than the sum of its proper divisors (18874429).

42129891 is a wasteful number, since it uses less digits than its factorization.

42129891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11546 (or 11543 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 42129891 is about 6490.7542704989. The cubic root of 42129891 is about 347.9606326851.

The spelling of 42129891 in words is "forty-two million, one hundred twenty-nine thousand, eight hundred ninety-one".