21703918 has 4 divisors (see below), whose sum is σ = 32555880. Its totient is φ = 10851958.

The previous prime is 21703897. The next prime is 21703967. The reversal of 21703918 is 81930712.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21703918.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5425978 + ... + 5425981.

It is an arithmetic number, because the mean of its divisors is an integer number (8138970).

Almost surely, 2^21703918 is an apocalyptic number.

21703918 is a deficient number, since it is larger than the sum of its proper divisors (10851962).

21703918 is a wasteful number, since it uses less digits than its factorization.

21703918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10851961.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 21703918 is about 4658.7463979058. The cubic root of 21703918 is about 278.9412310967.

The spelling of 21703918 in words is "twenty-one million, seven hundred three thousand, nine hundred eighteen".