660660220400 has 60 divisors (see below), whose sum is σ = 1607327853600. Its totient is φ = 260918960640.

The previous prime is 660660220387. The next prime is 660660220457. The reversal of 660660220400 is 4022066066.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10421885 + ... + 10485084.

It is an arithmetic number, because the mean of its divisors is an integer number (26788797560).

Almost surely, 2^660660220400 is an apocalyptic number.

It is an amenable number.

660660220400 is an abundant number, since it is smaller than the sum of its proper divisors (946667633200).

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

660660220400 is a wasteful number, since it uses less digits than its factorization.

660660220400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20907066 (or 20907055 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 32.

Adding to 660660220400 its reverse (4022066066), we get a palindrome (664682286466).

The spelling of 660660220400 in words is "six hundred sixty billion, six hundred sixty million, two hundred twenty thousand, four hundred".