21371356 has 12 divisors (see below), whose sum is σ = 37433592. Its totient is φ = 10676048.

The previous prime is 21371341. The next prime is 21371359. The reversal of 21371356 is 65317312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21371359) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5391 + ... + 8473.

It is an arithmetic number, because the mean of its divisors is an integer number (3119466).

Almost surely, 2^21371356 is an apocalyptic number.

It is an amenable number.

21371356 is a deficient number, since it is larger than the sum of its proper divisors (16062236).

21371356 is a wasteful number, since it uses less digits than its factorization.

21371356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4820 (or 4818 counting only the distinct ones).

The product of its digits is 3780, while the sum is 28.

The square root of 21371356 is about 4622.9163955235. The cubic root of 21371356 is about 277.5091834745.

Adding to 21371356 its reverse (65317312), we get a palindrome (86688668).

The spelling of 21371356 in words is "twenty-one million, three hundred seventy-one thousand, three hundred fifty-six".