661467688 has 64 divisors (see below), whose sum is σ = 1508855040. Its totient is φ = 265380864.

The previous prime is 661467683. The next prime is 661467701. The reversal of 661467688 is 886764166.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (661467683) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 185781 + ... + 189307.

It is an arithmetic number, because the mean of its divisors is an integer number (23575860).

Almost surely, 2^661467688 is an apocalyptic number.

661467688 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661467688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (754427520).

661467688 is an abundant number, since it is smaller than the sum of its proper divisors (847387352).

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

661467688 is a wasteful number, since it uses less digits than its factorization.

661467688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3754 (or 3750 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 52.

The square root of 661467688 is about 25719.0141335161. The cubic root of 661467688 is about 871.3036728433.

The spelling of 661467688 in words is "six hundred sixty-one million, four hundred sixty-seven thousand, six hundred eighty-eight".