21355436 has 12 divisors (see below), whose sum is σ = 37427040. Its totient is φ = 10662000.

The previous prime is 21355409. The next prime is 21355447. The reversal of 21355436 is 63455312.

It is a junction number, because it is equal to n+sod(n) for n = 21355399 and 21355408.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 551 + ... + 6558.

It is an arithmetic number, because the mean of its divisors is an integer number (3118920).

Almost surely, 2^21355436 is an apocalyptic number.

It is an amenable number.

21355436 is a deficient number, since it is larger than the sum of its proper divisors (16071604).

21355436 is a wasteful number, since it uses less digits than its factorization.

21355436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7864 (or 7862 counting only the distinct ones).

The product of its digits is 10800, while the sum is 29.

The square root of 21355436 is about 4621.1942179484. The cubic root of 21355436 is about 277.4402587626.

The spelling of 21355436 in words is "twenty-one million, three hundred fifty-five thousand, four hundred thirty-six".