661993142112 has 288 divisors, whose sum is σ = 2007372144960. Its totient is φ = 206599680000.

The previous prime is 661993142089. The next prime is 661993142117. The reversal of 661993142112 is 211241399166.

661993142112 is a `hidden beast` number, since 6 + 6 + 199 + 31 + 421 + 1 + 2 = 666.

661993142112 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (288).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661993142117) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 36163362 + ... + 36181662.

It is an arithmetic number, because the mean of its divisors is an integer number (6970042170).

Almost surely, 2^661993142112 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661993142112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1003686072480).

661993142112 is an abundant number, since it is smaller than the sum of its proper divisors (1345379002848).

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

661993142112 is a wasteful number, since it uses less digits than its factorization.

661993142112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18478 (or 18467 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The spelling of 661993142112 in words is "six hundred sixty-one billion, nine hundred ninety-three million, one hundred forty-two thousand, one hundred twelve".