42721551 has 12 divisors (see below), whose sum is σ = 62873928. Its totient is φ = 27943344.

The previous prime is 42721537. The next prime is 42721559. The reversal of 42721551 is 15512724.

42721551 is a `hidden beast` number, since 42 + 72 + 1 + 551 = 666.

42721551 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 42721551 - 2⁷ = 42721423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42721559) 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 11 ways as a sum of consecutive naturals, for example, 44305 + ... + 45258.

It is an arithmetic number, because the mean of its divisors is an integer number (5239494).

Almost surely, 2^42721551 is an apocalyptic number.

42721551 is a deficient number, since it is larger than the sum of its proper divisors (20152377).

42721551 is a wasteful number, since it uses less digits than its factorization.

42721551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89622 (or 89619 counting only the distinct ones).

The product of its digits is 2800, while the sum is 27.

The square root of 42721551 is about 6536.1725038435. The cubic root of 42721551 is about 349.5819525748.

The spelling of 42721551 in words is "forty-two million, seven hundred twenty-one thousand, five hundred fifty-one".