1666723402167 has 4 divisors (see below), whose sum is σ = 2222297869560. Its totient is φ = 1111148934776.

The previous prime is 1666723402159. The next prime is 1666723402193. The reversal of 1666723402167 is 7612043276661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1666723402167 - 2³ = 1666723402159 is a prime.

It is a super-2 number, since 2×1666723402167² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666723402067) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 277787233692 + ... + 277787233697.

It is an arithmetic number, because the mean of its divisors is an integer number (555574467390).

Almost surely, 2^{1666723402167} is an apocalyptic number.

1666723402167 is a deficient number, since it is larger than the sum of its proper divisors (555574467393).

1666723402167 is an equidigital number, since it uses as much as digits as its factorization.

1666723402167 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555574467392.

The product of its (nonzero) digits is 3048192, while the sum is 51.

The spelling of 1666723402167 in words is "one trillion, six hundred sixty-six billion, seven hundred twenty-three million, four hundred two thousand, one hundred sixty-seven".