255721531 has 8 divisors (see below), whose sum is σ = 291592224. Its totient is φ = 222165120.

The previous prime is 255721493. The next prime is 255721549. The reversal of 255721531 is 135127552.

255721531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 255721531 - 2¹¹ = 255719483 is a prime.

It is a super-2 number, since 2×255721531² = 130787002833967922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 255721493 and 255721502.

It is not an unprimeable number, because it can be changed into a prime (255721591) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 578335 + ... + 578776.

It is an arithmetic number, because the mean of its divisors is an integer number (36449028).

Almost surely, 2^255721531 is an apocalyptic number.

255721531 is a deficient number, since it is larger than the sum of its proper divisors (35870693).

255721531 is a wasteful number, since it uses less digits than its factorization.

255721531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1157141.

The product of its digits is 10500, while the sum is 31.

The square root of 255721531 is about 15991.2954759769. The cubic root of 255721531 is about 634.7301070579.

The spelling of 255721531 in words is "two hundred fifty-five million, seven hundred twenty-one thousand, five hundred thirty-one".