661701744 has 160 divisors (see below), whose sum is σ = 2194145280. Its totient is φ = 188697600.

The previous prime is 661701731. The next prime is 661701751. The reversal of 661701744 is 447107166.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 661701699 and 661701708.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 76689 + ... + 84879.

It is an arithmetic number, because the mean of its divisors is an integer number (13713408).

Almost surely, 2^661701744 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 661701744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1097072640).

661701744 is an abundant number, since it is smaller than the sum of its proper divisors (1532443536).

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

661701744 is a wasteful number, since it uses less digits than its factorization.

661701744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8236 (or 8224 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 36.

The square root of 661701744 is about 25723.5639832431. The cubic root of 661701744 is about 871.4064290864.

The spelling of 661701744 in words is "six hundred sixty-one million, seven hundred one thousand, seven hundred forty-four".