661144231 has 16 divisors (see below), whose sum is σ = 742025088. Its totient is φ = 583783200.

The previous prime is 661144201. The next prime is 661144241. The reversal of 661144231 is 132441166.

It is not a de Polignac number, because 661144231 - 2⁷ = 661144103 is a prime.

It is a super-2 number, since 2×661144231² = 874223388369162722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 661144231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661144201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 329076 + ... + 331078.

It is an arithmetic number, because the mean of its divisors is an integer number (46376568).

Almost surely, 2^661144231 is an apocalyptic number.

661144231 is a deficient number, since it is larger than the sum of its proper divisors (80880857).

661144231 is a wasteful number, since it uses less digits than its factorization.

661144231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2862.

The product of its digits is 3456, while the sum is 28.

The square root of 661144231 is about 25712.7250792288. The cubic root of 661144231 is about 871.1616274958.

Adding to 661144231 its reverse (132441166), we get a palindrome (793585397).

The spelling of 661144231 in words is "six hundred sixty-one million, one hundred forty-four thousand, two hundred thirty-one".