661272744 has 128 divisors (see below), whose sum is σ = 1843937280. Its totient is φ = 197588160.

The previous prime is 661272743. The next prime is 661272797. The reversal of 661272744 is 447272166.

It is not an unprimeable number, because it can be changed into a prime (661272743) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4056807 + ... + 4056969.

It is an arithmetic number, because the mean of its divisors is an integer number (14405760).

Almost surely, 2^661272744 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661272744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (921968640).

661272744 is an abundant number, since it is smaller than the sum of its proper divisors (1182664536).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661272744 is a wasteful number, since it uses less digits than its factorization.

661272744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332 (or 306 counting only the distinct ones).

The product of its digits is 112896, while the sum is 39.

The square root of 661272744 is about 25715.2239733587. The cubic root of 661272744 is about 871.2180692100.

It can be divided in two parts, 66 and 1272744, that added together give a triangular number (1272810 = T₁₅₉₅).

The spelling of 661272744 in words is "six hundred sixty-one million, two hundred seventy-two thousand, seven hundred forty-four".