52687721 has 4 divisors (see below), whose sum is σ = 52837332. Its totient is φ = 52538112.

The previous prime is 52687717. The next prime is 52687753. The reversal of 52687721 is 12778625.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 35581225 + 17106496 = 5965^2 + 4136^2 .

It is a cyclic number.

It is not a de Polignac number, because 52687721 - 2² = 52687717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (52687421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74276 + ... + 74981.

It is an arithmetic number, because the mean of its divisors is an integer number (13209333).

Almost surely, 2^52687721 is an apocalyptic number.

It is an amenable number.

52687721 is a deficient number, since it is larger than the sum of its proper divisors (149611).

52687721 is a wasteful number, since it uses less digits than its factorization.

52687721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149610.

The product of its digits is 47040, while the sum is 38.

The square root of 52687721 is about 7258.6307937517. The cubic root of 52687721 is about 374.8893801126.

The spelling of 52687721 in words is "fifty-two million, six hundred eighty-seven thousand, seven hundred twenty-one".