21751109392321 has 8 divisors (see below), whose sum is σ = 21759288275304. Its totient is φ = 21742932032640.

The previous prime is 21751109392319. The next prime is 21751109392357. The reversal of 21751109392321 is 12329390115712.

It can be written as a sum of positive squares in 4 ways, for example, as 2651491155600 + 19099618236721 = 1628340^2 + 4370311^2 .

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 21751109392321 - 2¹ = 21751109392319 is a prime.

It is a super-2 number, since 2×21751109392321² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21751109392421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28595295 + ... + 29346091.

It is an arithmetic number, because the mean of its divisors is an integer number (2719911034413).

Almost surely, 2^{21751109392321} is an apocalyptic number.

It is an amenable number.

21751109392321 is a deficient number, since it is larger than the sum of its proper divisors (8178882983).

21751109392321 is an equidigital number, since it uses as much as digits as its factorization.

21751109392321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 761651.

The product of its (nonzero) digits is 204120, while the sum is 46.

The spelling of 21751109392321 in words is "twenty-one trillion, seven hundred fifty-one billion, one hundred nine million, three hundred ninety-two thousand, three hundred twenty-one".