21621682347 has 8 divisors (see below), whose sum is σ = 28863942144. Its totient is φ = 14396938728.

The previous prime is 21621682343. The next prime is 21621682393. The reversal of 21621682347 is 74328612612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21621682347 - 2² = 21621682343 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21621682299 and 21621682308.

It is not an unprimeable number, because it can be changed into a prime (21621682343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4376163 + ... + 4381100.

It is an arithmetic number, because the mean of its divisors is an integer number (3607992768).

Almost surely, 2^21621682347 is an apocalyptic number.

21621682347 is a deficient number, since it is larger than the sum of its proper divisors (7242259797).

21621682347 is an equidigital number, since it uses as much as digits as its factorization.

21621682347 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8758089.

The product of its digits is 193536, while the sum is 42.

The spelling of 21621682347 in words is "twenty-one billion, six hundred twenty-one million, six hundred eighty-two thousand, three hundred forty-seven".