21731214 has 16 divisors (see below), whose sum is σ = 43781328. Its totient is φ = 7190592.

The previous prime is 21731191. The next prime is 21731239. The reversal of 21731214 is 41213712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12397 + ... + 14040.

It is an arithmetic number, because the mean of its divisors is an integer number (2736333).

Almost surely, 2^21731214 is an apocalyptic number.

21731214 is an abundant number, since it is smaller than the sum of its proper divisors (22050114).

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

21731214 is a wasteful number, since it uses less digits than its factorization.

21731214 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26579.

The product of its digits is 336, while the sum is 21.

The square root of 21731214 is about 4661.6750208482. The cubic root of 21731214 is about 279.0581192112.

Adding to 21731214 its reverse (41213712), we get a palindrome (62944926).

It can be divided in two parts, 21731 and 214, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 21731214 in words is "twenty-one million, seven hundred thirty-one thousand, two hundred fourteen".