661331052600 has 96 divisors (see below), whose sum is σ = 2051906489520. Its totient is φ = 176201809920.

The previous prime is 661331052553. The next prime is 661331052611. The reversal of 661331052600 is 6250133166.

It is a super-2 number, since 2×661331052600² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 213822 + ... + 1169778.

Almost surely, 2^661331052600 is an apocalyptic number.

661331052600 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 661331052600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1025953244760).

661331052600 is an abundant number, since it is smaller than the sum of its proper divisors (1390575436920).

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

661331052600 is a wasteful number, since it uses less digits than its factorization.

661331052600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 957129 (or 957120 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 33.

Adding to 661331052600 its reverse (6250133166), we get a palindrome (667581185766).

The spelling of 661331052600 in words is "six hundred sixty-one billion, three hundred thirty-one million, fifty-two thousand, six hundred".