5725731987721 has 4 divisors (see below), whose sum is σ = 5725795558212. Its totient is φ = 5725668417232.

The previous prime is 5725731987709. The next prime is 5725731987799. The reversal of 5725731987721 is 1277891375275.

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 2508232387600 + 3217499600121 = 1583740^2 + 1793739^2 .

It is a cyclic number.

It is not a de Polignac number, because 5725731987721 - 2³¹ = 5723584504073 is a prime.

It is a super-2 number, since 2×5725731987721² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (5725731981721) 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, 31649950 + ... + 31830343.

It is an arithmetic number, because the mean of its divisors is an integer number (1431448889553).

Almost surely, 2^{5725731987721} is an apocalyptic number.

It is an amenable number.

5725731987721 is a deficient number, since it is larger than the sum of its proper divisors (63570491).

5725731987721 is an equidigital number, since it uses as much as digits as its factorization.

5725731987721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63570490.

The product of its digits is 51861600, while the sum is 64.

The spelling of 5725731987721 in words is "five trillion, seven hundred twenty-five billion, seven hundred thirty-one million, nine hundred eighty-seven thousand, seven hundred twenty-one".