666731401200 has 960 divisors, whose sum is σ = 2501126584320. Its totient is φ = 168528936960.

The previous prime is 666731401177. The next prime is 666731401229. The reversal of 666731401200 is 2104137666.

It is a happy number.

It is a super-2 number, since 2×666731401200² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 3992403517 + ... + 3992403683.

It is an arithmetic number, because the mean of its divisors is an integer number (2605340192).

Almost surely, 2^666731401200 is an apocalyptic number.

666731401200 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 666731401200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1250563292160).

666731401200 is an abundant number, since it is smaller than the sum of its proper divisors (1834395183120).

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

666731401200 is a wasteful number, since it uses less digits than its factorization.

666731401200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431 (or 414 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 36.

Adding to 666731401200 its reverse (2104137666), we get a palindrome (668835538866).

The spelling of 666731401200 in words is "six hundred sixty-six billion, seven hundred thirty-one million, four hundred one thousand, two hundred".