21731196 has 12 divisors (see below), whose sum is σ = 50706152. Its totient is φ = 7243728.

The previous prime is 21731191. The next prime is 21731239. The reversal of 21731196 is 69113712.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21731191) 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, 905455 + ... + 905478.

Almost surely, 2^21731196 is an apocalyptic number.

It is an amenable number.

21731196 is an abundant number, since it is smaller than the sum of its proper divisors (28974956).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21731196 is a wasteful number, since it uses less digits than its factorization.

21731196 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1810940 (or 1810938 counting only the distinct ones).

The product of its digits is 2268, while the sum is 30.

The square root of 21731196 is about 4661.6730902113. The cubic root of 21731196 is about 279.0580421630.

It can be divided in two parts, 217 and 31196, that added together give a palindrome (31413).

The spelling of 21731196 in words is "twenty-one million, seven hundred thirty-one thousand, one hundred ninety-six".