21106751747 has 4 divisors (see below), whose sum is σ = 21504992400. Its totient is φ = 20708511096.

The previous prime is 21106751737. The next prime is 21106751773. The reversal of 21106751747 is 74715760112.

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

It is a cyclic number.

It is not a de Polignac number, because 21106751747 - 2⁶ = 21106751683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21106751707) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 199120247 + ... + 199120352.

It is an arithmetic number, because the mean of its divisors is an integer number (5376248100).

Almost surely, 2^21106751747 is an apocalyptic number.

21106751747 is a deficient number, since it is larger than the sum of its proper divisors (398240653).

21106751747 is an equidigital number, since it uses as much as digits as its factorization.

21106751747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 398240652.

The product of its (nonzero) digits is 82320, while the sum is 41.

The spelling of 21106751747 in words is "twenty-one billion, one hundred six million, seven hundred fifty-one thousand, seven hundred forty-seven".