42191021 has 8 divisors (see below), whose sum is σ = 43110144. Its totient is φ = 41276560.

The previous prime is 42191011. The next prime is 42191053. The reversal of 42191021 is 12019124.

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 42191021 - 2¹⁰ = 42189997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 42190984 and 42191002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42191011) 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, 21920 + ... + 23766.

It is an arithmetic number, because the mean of its divisors is an integer number (5388768).

Almost surely, 2^42191021 is an apocalyptic number.

It is an amenable number.

42191021 is a deficient number, since it is larger than the sum of its proper divisors (919123).

42191021 is a wasteful number, since it uses less digits than its factorization.

42191021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2331.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 42191021 is about 6495.4615694345. The cubic root of 42191021 is about 348.1288470126.

The spelling of 42191021 in words is "forty-two million, one hundred ninety-one thousand, twenty-one".