21311657105 has 8 divisors (see below), whose sum is σ = 25574812992. Its totient is φ = 17048776048.

The previous prime is 21311657089. The next prime is 21311657189. The reversal of 21311657105 is 50175611312.

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

It is a cyclic number.

It is not a de Polignac number, because 21311657105 - 2⁴ = 21311657089 is a prime.

It is a super-2 number, since 2×21311657105² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 191462 + ... + 281568.

It is an arithmetic number, because the mean of its divisors is an integer number (3196851624).

Almost surely, 2^21311657105 is an apocalyptic number.

It is an amenable number.

21311657105 is a deficient number, since it is larger than the sum of its proper divisors (4263155887).

21311657105 is an equidigital number, since it uses as much as digits as its factorization.

21311657105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137415.

The product of its (nonzero) digits is 6300, while the sum is 32.

The spelling of 21311657105 in words is "twenty-one billion, three hundred eleven million, six hundred fifty-seven thousand, one hundred five".