21355704 has 32 divisors (see below), whose sum is σ = 59322000. Its totient is φ = 7118496.

The previous prime is 21355693. The next prime is 21355717. The reversal of 21355704 is 40755312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 49219 + ... + 49650.

Almost surely, 2^21355704 is an apocalyptic number.

21355704 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21355704 is an abundant number, since it is smaller than the sum of its proper divisors (37966296).

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

21355704 is a wasteful number, since it uses less digits than its factorization.

21355704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98884 (or 98874 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 27.

The square root of 21355704 is about 4621.2232146911. The cubic root of 21355704 is about 277.4414193364.

The spelling of 21355704 in words is "twenty-one million, three hundred fifty-five thousand, seven hundred four".