661701600 has 432 divisors, whose sum is σ = 2811070080. Its totient is φ = 143078400.

The previous prime is 661701571. The next prime is 661701629. The reversal of 661701600 is 6107166.

661701600 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (661701571) and next prime (661701629).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 957255 + ... + 957945.

Almost surely, 2^661701600 is an apocalyptic number.

661701600 is a gapful number since it is divisible by the number (60) 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 661701600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1405535040).

661701600 is an abundant number, since it is smaller than the sum of its proper divisors (2149368480).

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

661701600 is a wasteful number, since it uses less digits than its factorization.

661701600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 743 (or 727 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 661701600 is about 25723.5611842529. The cubic root of 661701600 is about 871.4063658743.

Adding to 661701600 its reverse (6107166), we get a palindrome (667808766).

The spelling of 661701600 in words is "six hundred sixty-one million, seven hundred one thousand, six hundred".