21176920751 has 4 divisors (see below), whose sum is σ = 24202195152. Its totient is φ = 18151646352.

The previous prime is 21176920711. The next prime is 21176920777. The reversal of 21176920751 is 15702967112.

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

It is not a de Polignac number, because 21176920751 - 2¹⁰ = 21176919727 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21176920699 and 21176920708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21176920711) 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, 1512637190 + ... + 1512637203.

It is an arithmetic number, because the mean of its divisors is an integer number (6050548788).

Almost surely, 2^21176920751 is an apocalyptic number.

21176920751 is a deficient number, since it is larger than the sum of its proper divisors (3025274401).

21176920751 is an equidigital number, since it uses as much as digits as its factorization.

21176920751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3025274400.

The product of its (nonzero) digits is 52920, while the sum is 41.

The spelling of 21176920751 in words is "twenty-one billion, one hundred seventy-six million, nine hundred twenty thousand, seven hundred fifty-one".