668215001780 has 48 divisors (see below), whose sum is σ = 1480067400000. Its totient is φ = 252710793216.

The previous prime is 668215001759. The next prime is 668215001789. The reversal of 668215001780 is 87100512866.

It is a happy number.

It is a super-2 number, since 2×668215001780² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668215001789) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1572365 + ... + 1951604.

It is an arithmetic number, because the mean of its divisors is an integer number (30834737500).

Almost surely, 2^668215001780 is an apocalyptic number.

It is an amenable number.

668215001780 is an abundant number, since it is smaller than the sum of its proper divisors (811852398220).

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

668215001780 is a wasteful number, since it uses less digits than its factorization.

668215001780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3524496 (or 3524494 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 44.

The spelling of 668215001780 in words is "six hundred sixty-eight billion, two hundred fifteen million, one thousand, seven hundred eighty".