21671270 has 24 divisors (see below), whose sum is σ = 40116384. Its totient is φ = 8428896.

The previous prime is 21671261. The next prime is 21671297. The reversal of 21671270 is 7217612.

It is a super-3 number, since 3×21671270³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12899 + ... + 14481.

It is an arithmetic number, because the mean of its divisors is an integer number (1671516).

Almost surely, 2^21671270 is an apocalyptic number.

21671270 is a deficient number, since it is larger than the sum of its proper divisors (18445114).

21671270 is a wasteful number, since it uses less digits than its factorization.

21671270 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1664 (or 1627 counting only the distinct ones).

The product of its (nonzero) digits is 1176, while the sum is 26.

The square root of 21671270 is about 4655.2411323153. The cubic root of 21671270 is about 278.8012956335.

Adding to 21671270 its reverse (7217612), we get a palindrome (28888882).

The spelling of 21671270 in words is "twenty-one million, six hundred seventy-one thousand, two hundred seventy".