661001560 has 16 divisors (see below), whose sum is σ = 1487253600. Its totient is φ = 264400608.

The previous prime is 661001521. The next prime is 661001563. The reversal of 661001560 is 65100166.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661001563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8262480 + ... + 8262559.

It is an arithmetic number, because the mean of its divisors is an integer number (92953350).

Almost surely, 2^661001560 is an apocalyptic number.

It is an amenable number.

661001560 is an abundant number, since it is smaller than the sum of its proper divisors (826252040).

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

661001560 is a wasteful number, since it uses less digits than its factorization.

661001560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16525050 (or 16525046 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 661001560 is about 25709.9506028308. The cubic root of 661001560 is about 871.0989591520.

The spelling of 661001560 in words is "six hundred sixty-one million, one thousand, five hundred sixty".