42630921 has 32 divisors (see below), whose sum is σ = 66493440. Its totient is φ = 26984880.

The previous prime is 42630901. The next prime is 42630949. The reversal of 42630921 is 12903624.

42630921 is a `hidden beast` number, since 4 + 2 + 630 + 9 + 21 = 666.

42630921 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 42630921 - 2⁷ = 42630793 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (42630901) 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, 804331 + ... + 804383.

It is an arithmetic number, because the mean of its divisors is an integer number (2077920).

Almost surely, 2^42630921 is an apocalyptic number.

It is an amenable number.

42630921 is a deficient number, since it is larger than the sum of its proper divisors (23862519).

42630921 is an frugal number, since it uses more digits than its factorization.

42630921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155 (or 87 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 42630921 is about 6529.2358664701. The cubic root of 42630921 is about 349.3345751426.

The spelling of 42630921 in words is "forty-two million, six hundred thirty thousand, nine hundred twenty-one".