655249581 has 40 divisors (see below), whose sum is σ = 1184483520. Its totient is φ = 352397952.

The previous prime is 655249541. The next prime is 655249583. The reversal of 655249581 is 185942556.

655249581 is a `hidden beast` number, since 6 + 552 + 4 + 95 + 8 + 1 = 666.

It is not a de Polignac number, because 655249581 - 2⁹ = 655249069 is a prime.

It is a super-2 number, since 2×655249581² = 858704026801351122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (655249583) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 24351 + ... + 43628.

It is an arithmetic number, because the mean of its divisors is an integer number (29612088).

Almost surely, 2^655249581 is an apocalyptic number.

It is an amenable number.

655249581 is a deficient number, since it is larger than the sum of its proper divisors (529233939).

655249581 is a wasteful number, since it uses less digits than its factorization.

655249581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68015 (or 68006 counting only the distinct ones).

The product of its digits is 432000, while the sum is 45.

The square root of 655249581 is about 25597.8432880585. The cubic root of 655249581 is about 868.5648514846.

The spelling of 655249581 in words is "six hundred fifty-five million, two hundred forty-nine thousand, five hundred eighty-one".