21242623566 has 16 divisors (see below), whose sum is σ = 42562923264. Its totient is φ = 7067928504.

The previous prime is 21242623559. The next prime is 21242623573. The reversal of 21242623566 is 66532624212.

It is an interprime number because it is at equal distance from previous prime (21242623559) and next prime (21242623573).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3232950 + ... + 3239513.

It is an arithmetic number, because the mean of its divisors is an integer number (2660182704).

Almost surely, 2^21242623566 is an apocalyptic number.

21242623566 is an abundant number, since it is smaller than the sum of its proper divisors (21320299698).

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

21242623566 is a wasteful number, since it uses less digits than its factorization.

21242623566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6473015.

The product of its digits is 207360, while the sum is 39.

The spelling of 21242623566 in words is "twenty-one billion, two hundred forty-two million, six hundred twenty-three thousand, five hundred sixty-six".