21623910911 has 4 divisors (see below), whose sum is σ = 21624207672. Its totient is φ = 21623614152.

The previous prime is 21623910881. The next prime is 21623910941. The reversal of 21623910911 is 11901932612.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (21623910881) and next prime (21623910941).

It is a cyclic number.

It is not a de Polignac number, because 21623910911 - 2¹⁴ = 21623894527 is a prime.

It is a super-3 number, since 3×21623910911³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21623910941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44465 + ... + 212661.

It is an arithmetic number, because the mean of its divisors is an integer number (5406051918).

Almost surely, 2^21623910911 is an apocalyptic number.

21623910911 is a deficient number, since it is larger than the sum of its proper divisors (296761).

21623910911 is a wasteful number, since it uses less digits than its factorization.

21623910911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296760.

The product of its (nonzero) digits is 5832, while the sum is 35.

The spelling of 21623910911 in words is "twenty-one billion, six hundred twenty-three million, nine hundred ten thousand, nine hundred eleven".