661893560 has 32 divisors (see below), whose sum is σ = 1492290000. Its totient is φ = 264218880.

The previous prime is 661893541. The next prime is 661893571. The reversal of 661893560 is 65398166.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3380 + ... + 36540.

Almost surely, 2^661893560 is an apocalyptic number.

It is an amenable number.

661893560 is an abundant number, since it is smaller than the sum of its proper divisors (830396440).

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

661893560 is a wasteful number, since it uses less digits than its factorization.

661893560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33671 (or 33667 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 44.

The square root of 661893560 is about 25727.2921233464. The cubic root of 661893560 is about 871.4906228834.

The spelling of 661893560 in words is "six hundred sixty-one million, eight hundred ninety-three thousand, five hundred sixty".