21355356 has 24 divisors (see below), whose sum is σ = 54359424. Its totient is φ = 6471280.

The previous prime is 21355351. The next prime is 21355387. The reversal of 21355356 is 65355312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21355351) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80760 + ... + 81023.

It is an arithmetic number, because the mean of its divisors is an integer number (2264976).

Almost surely, 2^21355356 is an apocalyptic number.

It is an amenable number.

21355356 is an abundant number, since it is smaller than the sum of its proper divisors (33004068).

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

21355356 is a wasteful number, since it uses less digits than its factorization.

21355356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161801 (or 161799 counting only the distinct ones).

The product of its digits is 13500, while the sum is 30.

The square root of 21355356 is about 4621.1855621691. The cubic root of 21355356 is about 277.4399123208.

The spelling of 21355356 in words is "twenty-one million, three hundred fifty-five thousand, three hundred fifty-six".