21712260 has 24 divisors (see below), whose sum is σ = 60794496. Its totient is φ = 5789920.

The previous prime is 21712259. The next prime is 21712267. The reversal of 21712260 is 6221712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21712267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 180876 + ... + 180995.

It is an arithmetic number, because the mean of its divisors is an integer number (2533104).

Almost surely, 2^21712260 is an apocalyptic number.

21712260 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21712260 is an abundant number, since it is smaller than the sum of its proper divisors (39082236).

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

21712260 is a wasteful number, since it uses less digits than its factorization.

21712260 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361883 (or 361881 counting only the distinct ones).

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

The square root of 21712260 is about 4659.6416171204. The cubic root of 21712260 is about 278.9769639644.

Adding to 21712260 its reverse (6221712), we get a palindrome (27933972).

The spelling of 21712260 in words is "twenty-one million, seven hundred twelve thousand, two hundred sixty".