19971018166 has 32 divisors (see below), whose sum is σ = 33634932480. Its totient is φ = 8816253600.

The previous prime is 19971018149. The next prime is 19971018167. The reversal of 19971018166 is 66181017991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19971018167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9240 + ... + 200068.

It is an arithmetic number, because the mean of its divisors is an integer number (1051091640).

Almost surely, 2^19971018166 is an apocalyptic number.

19971018166 is a deficient number, since it is larger than the sum of its proper divisors (13663914314).

19971018166 is a wasteful number, since it uses less digits than its factorization.

19971018166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190980.

The product of its (nonzero) digits is 163296, while the sum is 49.

The spelling of 19971018166 in words is "nineteen billion, nine hundred seventy-one million, eighteen thousand, one hundred sixty-six".