21031742171 has 12 divisors (see below), whose sum is σ = 23346434832. Its totient is φ = 18930450000.

The previous prime is 21031742129. The next prime is 21031742177. The reversal of 21031742171 is 17124713012.

It is not a de Polignac number, because 21031742171 - 2⁶ = 21031742107 is a prime.

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21031742177) 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, 848255 + ... + 872696.

It is an arithmetic number, because the mean of its divisors is an integer number (1945536236).

Almost surely, 2^21031742171 is an apocalyptic number.

21031742171 is a deficient number, since it is larger than the sum of its proper divisors (2314692661).

21031742171 is a wasteful number, since it uses less digits than its factorization.

21031742171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1721074 (or 1721063 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 29.

The spelling of 21031742171 in words is "twenty-one billion, thirty-one million, seven hundred forty-two thousand, one hundred seventy-one".