42021999 has 6 divisors (see below), whose sum is σ = 60698456. Its totient is φ = 28014660.

The previous prime is 42021997. The next prime is 42022031. The reversal of 42021999 is 99912024.

It is not a de Polignac number, because 42021999 - 2¹ = 42021997 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 (42021997) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2334547 + ... + 2334564.

Almost surely, 2^42021999 is an apocalyptic number.

42021999 is a deficient number, since it is larger than the sum of its proper divisors (18676457).

42021999 is a wasteful number, since it uses less digits than its factorization.

42021999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4669117 (or 4669114 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 42021999 is about 6482.4377359139. The cubic root of 42021999 is about 347.6633436656.

The spelling of 42021999 in words is "forty-two million, twenty-one thousand, nine hundred ninety-nine".