21671310 has 16 divisors (see below), whose sum is σ = 52011216. Its totient is φ = 5779008.

The previous prime is 21671297. The next prime is 21671327. The reversal of 21671310 is 1317612.

It is a super-2 number, since 2×21671310² = 939291354232200, which contains 22 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 7 ways as a sum of consecutive naturals, for example, 361159 + ... + 361218.

It is an arithmetic number, because the mean of its divisors is an integer number (3250701).

Almost surely, 2^21671310 is an apocalyptic number.

21671310 is an abundant number, since it is smaller than the sum of its proper divisors (30339906).

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

21671310 is a wasteful number, since it uses less digits than its factorization.

21671310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 722387.

The product of its (nonzero) digits is 252, while the sum is 21.

The square root of 21671310 is about 4655.2454285462. The cubic root of 21671310 is about 278.8014671670.

Adding to 21671310 its reverse (1317612), we get a palindrome (22988922).

The spelling of 21671310 in words is "twenty-one million, six hundred seventy-one thousand, three hundred ten".