21371316 has 12 divisors (see below), whose sum is σ = 49866432. Its totient is φ = 7123768.

The previous prime is 21371299. The next prime is 21371341. The reversal of 21371316 is 61317312.

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

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 890460 + ... + 890483.

It is an arithmetic number, because the mean of its divisors is an integer number (4155536).

Almost surely, 2^21371316 is an apocalyptic number.

It is an amenable number.

21371316 is an abundant number, since it is smaller than the sum of its proper divisors (28495116).

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

21371316 is a wasteful number, since it uses less digits than its factorization.

21371316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1780950 (or 1780948 counting only the distinct ones).

The product of its digits is 756, while the sum is 24.

The square root of 21371316 is about 4622.9120692481. The cubic root of 21371316 is about 277.5090103397.

Adding to 21371316 its reverse (61317312), we get a palindrome (82688628).

The spelling of 21371316 in words is "twenty-one million, three hundred seventy-one thousand, three hundred sixteen".