42721164 has 18 divisors (see below), whose sum is σ = 107989700. Its totient is φ = 14240376.

The previous prime is 42721163. The next prime is 42721169. The reversal of 42721164 is 46112724.

It is a tau number, because it is divible by the number of its divisors (18).

It is not an unprimeable number, because it can be changed into a prime (42721163) 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, 593314 + ... + 593385.

Almost surely, 2^42721164 is an apocalyptic number.

It is an amenable number.

42721164 is an abundant number, since it is smaller than the sum of its proper divisors (65268536).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

42721164 is a wasteful number, since it uses less digits than its factorization.

42721164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1186709 (or 1186704 counting only the distinct ones).

The product of its digits is 2688, while the sum is 27.

The square root of 42721164 is about 6536.1428992947. The cubic root of 42721164 is about 349.5808969902.

Adding to 42721164 its reverse (46112724), we get a palindrome (88833888).

The spelling of 42721164 in words is "forty-two million, seven hundred twenty-one thousand, one hundred sixty-four".