661530144 has 96 divisors (see below), whose sum is σ = 1994146560. Its totient is φ = 189907200.

The previous prime is 661530131. The next prime is 661530157. The reversal of 661530144 is 441035166.

It is an interprime number because it is at equal distance from previous prime (661530131) and next prime (661530157).

It is a tau number, because it is divible by the number of its divisors (96).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3579 + ... + 36549.

It is an arithmetic number, because the mean of its divisors is an integer number (20772360).

Almost surely, 2^661530144 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 661530144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (997073280).

661530144 is an abundant number, since it is smaller than the sum of its proper divisors (1332616416).

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

661530144 is a wasteful number, since it uses less digits than its factorization.

661530144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33014 (or 33006 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 661530144 is about 25720.2283038079. The cubic root of 661530144 is about 871.3310949081.

The spelling of 661530144 in words is "six hundred sixty-one million, five hundred thirty thousand, one hundred forty-four".