42129021 has 8 divisors (see below), whose sum is σ = 61278624. Its totient is φ = 25532720.

The previous prime is 42129001. The next prime is 42129037. The reversal of 42129021 is 12092124.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 42129021 - 2²¹ = 40031869 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42129001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 638286 + ... + 638351.

It is an arithmetic number, because the mean of its divisors is an integer number (7659828).

Almost surely, 2^42129021 is an apocalyptic number.

It is an amenable number.

42129021 is a deficient number, since it is larger than the sum of its proper divisors (19149603).

42129021 is a wasteful number, since it uses less digits than its factorization.

42129021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1276651.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 42129021 is about 6490.6872517477. The cubic root of 42129021 is about 347.9582374907.

The spelling of 42129021 in words is "forty-two million, one hundred twenty-nine thousand, twenty-one".