42651021 has 32 divisors (see below), whose sum is σ = 66976000. Its totient is φ = 24131520.

The previous prime is 42651019. The next prime is 42651109. The reversal of 42651021 is 12015624.

42651021 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 42651021 - 2¹ = 42651019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42651001) 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 31 ways as a sum of consecutive naturals, for example, 186135 + ... + 186363.

It is an arithmetic number, because the mean of its divisors is an integer number (2093000).

Almost surely, 2^42651021 is an apocalyptic number.

It is an amenable number.

42651021 is a deficient number, since it is larger than the sum of its proper divisors (24324979).

42651021 is a wasteful number, since it uses less digits than its factorization.

42651021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434 (or 420 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 42651021 is about 6530.7749157355. The cubic root of 42651021 is about 349.3894689579.

Adding to 42651021 its reverse (12015624), we get a palindrome (54666645).

The spelling of 42651021 in words is "forty-two million, six hundred fifty-one thousand, twenty-one".