42721989 has 4 divisors (see below), whose sum is σ = 56962656. Its totient is φ = 28481324.

The previous prime is 42721981. The next prime is 42722027. The reversal of 42721989 is 98912724.

42721989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 42721989 - 2³ = 42721981 is a prime.

It is a super-2 number, since 2×42721989² = 3650336688232242, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 42721989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42721981) 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 3 ways as a sum of consecutive naturals, for example, 7120329 + ... + 7120334.

It is an arithmetic number, because the mean of its divisors is an integer number (14240664).

Almost surely, 2^42721989 is an apocalyptic number.

It is an amenable number.

42721989 is a deficient number, since it is larger than the sum of its proper divisors (14240667).

42721989 is a wasteful number, since it uses less digits than its factorization.

42721989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14240666.

The product of its digits is 72576, while the sum is 42.

The square root of 42721989 is about 6536.2060096053. The cubic root of 42721989 is about 349.5831472596.

The spelling of 42721989 in words is "forty-two million, seven hundred twenty-one thousand, nine hundred eighty-nine".