21670368 has 24 divisors (see below), whose sum is σ = 56884968. Its totient is φ = 7223424.

The previous prime is 21670339. The next prime is 21670373. The reversal of 21670368 is 86307612.

It is a tau number, because it is divible by the number of its divisors (24).

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, 112771 + ... + 112962.

It is an arithmetic number, because the mean of its divisors is an integer number (2370207).

Almost surely, 2^21670368 is an apocalyptic number.

It is an amenable number.

21670368 is an abundant number, since it is smaller than the sum of its proper divisors (35214600).

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

21670368 is a wasteful number, since it uses less digits than its factorization.

21670368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225746 (or 225738 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 21670368 is about 4655.1442512558. The cubic root of 21670368 is about 278.7974274975.

The spelling of 21670368 in words is "twenty-one million, six hundred seventy thousand, three hundred sixty-eight".