1666723867240 has 64 divisors (see below), whose sum is σ = 3965517803520. Its totient is φ = 629447232000.

The previous prime is 1666723867169. The next prime is 1666723867241. The reversal of 1666723867240 is 427683276661.

It is a super-2 number, since 2×1666723867240² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1666723867241) 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, 16341016 + ... + 16442695.

It is an arithmetic number, because the mean of its divisors is an integer number (61961215680).

Almost surely, 2^{1666723867240} is an apocalyptic number.

1666723867240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1666723867240 is an abundant number, since it is smaller than the sum of its proper divisors (2298793936280).

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

1666723867240 is a wasteful number, since it uses less digits than its factorization.

1666723867240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32783794 (or 32783790 counting only the distinct ones).

The product of its (nonzero) digits is 24385536, while the sum is 58.

The spelling of 1666723867240 in words is "one trillion, six hundred sixty-six billion, seven hundred twenty-three million, eight hundred sixty-seven thousand, two hundred forty".