21623355389 has 4 divisors (see below), whose sum is σ = 21624707424. Its totient is φ = 21622003356.

The previous prime is 21623355373. The next prime is 21623355409. The reversal of 21623355389 is 98355332612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21623355389 - 2⁴ = 21623355373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21623355889) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 651737 + ... + 684110.

It is an arithmetic number, because the mean of its divisors is an integer number (5406176856).

Almost surely, 2^21623355389 is an apocalyptic number.

It is an amenable number.

21623355389 is a deficient number, since it is larger than the sum of its proper divisors (1352035).

21623355389 is a wasteful number, since it uses less digits than its factorization.

21623355389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1352034.

The product of its digits is 1166400, while the sum is 47.

The spelling of 21623355389 in words is "twenty-one billion, six hundred twenty-three million, three hundred fifty-five thousand, three hundred eighty-nine".