661018752 has 128 divisors (see below), whose sum is σ = 2065867200. Its totient is φ = 207360000.

The previous prime is 661018741. The next prime is 661018783. The reversal of 661018752 is 257810166.

It is a tau number, because it is divible by the number of its divisors (128).

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

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53127 + ... + 64377.

Almost surely, 2^661018752 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 661018752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1032933600).

661018752 is an abundant number, since it is smaller than the sum of its proper divisors (1404848448).

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

661018752 is a wasteful number, since it uses less digits than its factorization.

661018752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11291 (or 11273 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 661018752 is about 25710.2849459122. The cubic root of 661018752 is about 871.1065112287.

The spelling of 661018752 in words is "six hundred sixty-one million, eighteen thousand, seven hundred fifty-two".