21643702 has 4 divisors (see below), whose sum is σ = 32465556. Its totient is φ = 10821850.

The previous prime is 21643693. The next prime is 21643723. The reversal of 21643702 is 20734612.

It is a semiprime because it is the product of two primes.

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 as a sum of consecutive naturals, namely, 5410924 + ... + 5410927.

It is an arithmetic number, because the mean of its divisors is an integer number (8116389).

Almost surely, 2^21643702 is an apocalyptic number.

21643702 is a deficient number, since it is larger than the sum of its proper divisors (10821854).

21643702 is a wasteful number, since it uses less digits than its factorization.

21643702 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10821853.

The product of its (nonzero) digits is 2016, while the sum is 25.

The square root of 21643702 is about 4652.2792263578. The cubic root of 21643702 is about 278.6830245225.

The spelling of 21643702 in words is "twenty-one million, six hundred forty-three thousand, seven hundred two".