42721380 has 72 divisors (see below), whose sum is σ = 139564152. Its totient is φ = 10515456.

The previous prime is 42721363. The next prime is 42721387. The reversal of 42721380 is 8312724.

It can be written as a sum of positive squares in 4 ways, for example, as 28224 + 42693156 = 168^2 + 6534^2 .

It is not an unprimeable number, because it can be changed into a prime (42721387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6789 + ... + 11468.

It is an arithmetic number, because the mean of its divisors is an integer number (1938391).

Almost surely, 2^42721380 is an apocalyptic number.

It is an amenable number.

42721380 is an abundant number, since it is smaller than the sum of its proper divisors (96842772).

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

42721380 is a wasteful number, since it uses less digits than its factorization.

42721380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18285 (or 18280 counting only the distinct ones).

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

The square root of 42721380 is about 6536.1594227803. The cubic root of 42721380 is about 349.5814861545.

The spelling of 42721380 in words is "forty-two million, seven hundred twenty-one thousand, three hundred eighty".