661145331 has 24 divisors (see below), whose sum is σ = 1107377152. Its totient is φ = 343450800.

The previous prime is 661145297. The next prime is 661145357. The reversal of 661145331 is 133541166.

It is not a de Polignac number, because 661145331 - 2⁷ = 661145203 is a prime.

It is a super-2 number, since 2×661145331² = 874226297406199122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (661145371) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 127555 + ... + 132636.

Almost surely, 2^661145331 is an apocalyptic number.

661145331 is a deficient number, since it is larger than the sum of its proper divisors (446231821).

661145331 is a wasteful number, since it uses less digits than its factorization.

661145331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260223 (or 260212 counting only the distinct ones).

The product of its digits is 6480, while the sum is 30.

The square root of 661145331 is about 25712.7464694070. The cubic root of 661145331 is about 871.1621106366.

Adding to 661145331 its reverse (133541166), we get a palindrome (794686497).

The spelling of 661145331 in words is "six hundred sixty-one million, one hundred forty-five thousand, three hundred thirty-one".