20691171 has 12 divisors (see below), whose sum is σ = 31460520. Its totient is φ = 13068000.

The previous prime is 20691149. The next prime is 20691197. The reversal of 20691171 is 17119602.

It is not a de Polignac number, because 20691171 - 2¹⁰ = 20690147 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20691131) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 60330 + ... + 60671.

It is an arithmetic number, because the mean of its divisors is an integer number (2621710).

Almost surely, 2^20691171 is an apocalyptic number.

20691171 is a deficient number, since it is larger than the sum of its proper divisors (10769349).

20691171 is a wasteful number, since it uses less digits than its factorization.

20691171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121026 (or 121023 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 27.

The square root of 20691171 is about 4548.7548845811. The cubic root of 20691171 is about 274.5332954526.

It can be divided in two parts, 20691 and 171, that multiplied together give a square (3538161 = 1881²).

The spelling of 20691171 in words is "twenty million, six hundred ninety-one thousand, one hundred seventy-one".