166987777711 has 4 divisors (see below), whose sum is σ = 170138490552. Its totient is φ = 163837064872.

The previous prime is 166987777679. The next prime is 166987777721. The reversal of 166987777711 is 117777789661.

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 166987777711 - 2⁵ = 166987777679 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166987777721) 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, 1575356341 + ... + 1575356446.

It is an arithmetic number, because the mean of its divisors is an integer number (42534622638).

Almost surely, 2^166987777711 is an apocalyptic number.

166987777711 is a deficient number, since it is larger than the sum of its proper divisors (3150712841).

166987777711 is an equidigital number, since it uses as much as digits as its factorization.

166987777711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3150712840.

The product of its digits is 43563744, while the sum is 67.

The spelling of 166987777711 in words is "one hundred sixty-six billion, nine hundred eighty-seven million, seven hundred seventy-seven thousand, seven hundred eleven".