21326583651 has 4 divisors (see below), whose sum is σ = 28435444872. Its totient is φ = 14217722432.

The previous prime is 21326583631. The next prime is 21326583659. The reversal of 21326583651 is 15638562312.

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

It is a cyclic number.

It is not a de Polignac number, because 21326583651 - 2²⁶ = 21259474787 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21326583659) 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, 3554430606 + ... + 3554430611.

It is an arithmetic number, because the mean of its divisors is an integer number (7108861218).

Almost surely, 2^21326583651 is an apocalyptic number.

21326583651 is a deficient number, since it is larger than the sum of its proper divisors (7108861221).

21326583651 is an equidigital number, since it uses as much as digits as its factorization.

21326583651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7108861220.

The product of its digits is 259200, while the sum is 42.

The spelling of 21326583651 in words is "twenty-one billion, three hundred twenty-six million, five hundred eighty-three thousand, six hundred fifty-one".