21220684726 has 4 divisors (see below), whose sum is σ = 31831027092. Its totient is φ = 10610342362.

The previous prime is 21220684699. The next prime is 21220684753. The reversal of 21220684726 is 62748602212.

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

It is an interprime number because it is at equal distance from previous prime (21220684699) and next prime (21220684753).

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, 5305171180 + ... + 5305171183.

It is an arithmetic number, because the mean of its divisors is an integer number (7957756773).

Almost surely, 2^21220684726 is an apocalyptic number.

21220684726 is a deficient number, since it is larger than the sum of its proper divisors (10610342366).

21220684726 is a wasteful number, since it uses less digits than its factorization.

21220684726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10610342365.

The product of its (nonzero) digits is 129024, while the sum is 40.

The spelling of 21220684726 in words is "twenty-one billion, two hundred twenty million, six hundred eighty-four thousand, seven hundred twenty-six".