21326839357 has 4 divisors (see below), whose sum is σ = 21327134976. Its totient is φ = 21326543740.

The previous prime is 21326839321. The next prime is 21326839399. The reversal of 21326839357 is 75393862312.

It is a happy number.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21326839357 - 2¹⁹ = 21326315069 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21326839357.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21326839657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39678 + ... + 210304.

It is an arithmetic number, because the mean of its divisors is an integer number (5331783744).

Almost surely, 2^21326839357 is an apocalyptic number.

It is an amenable number.

21326839357 is a deficient number, since it is larger than the sum of its proper divisors (295619).

21326839357 is a wasteful number, since it uses less digits than its factorization.

21326839357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295618.

The product of its digits is 1632960, while the sum is 49.

The spelling of 21326839357 in words is "twenty-one billion, three hundred twenty-six million, eight hundred thirty-nine thousand, three hundred fifty-seven".