21051691526747 has 8 divisors (see below), whose sum is σ = 25474315797216. Its totient is φ = 16982877197952.

The previous prime is 21051691526731. The next prime is 21051691526809. The reversal of 21051691526747 is 74762519615012.

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 21051691526747 - 2⁴ = 21051691526731 is a prime.

It is a super-2 number, since 2×21051691526747² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21051691526692 and 21051691526701.

It is not an unprimeable number, because it can be changed into a prime (21051691520747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88452485288 + ... + 88452485525.

It is an arithmetic number, because the mean of its divisors is an integer number (3184289474652).

Almost surely, 2^{21051691526747} is an apocalyptic number.

21051691526747 is a deficient number, since it is larger than the sum of its proper divisors (4422624270469).

21051691526747 is a wasteful number, since it uses less digits than its factorization.

21051691526747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176904970837.

The product of its (nonzero) digits is 6350400, while the sum is 56.

The spelling of 21051691526747 in words is "twenty-one trillion, fifty-one billion, six hundred ninety-one million, five hundred twenty-six thousand, seven hundred forty-seven".