21121301747 has 16 divisors (see below), whose sum is σ = 26169931200. Its totient is φ = 16599192192.

The previous prime is 21121301743. The next prime is 21121301771. The reversal of 21121301747 is 74710312112.

It is a cyclic number.

It is not a de Polignac number, because 21121301747 - 2² = 21121301743 is a prime.

It is a super-2 number, since 2×21121301747² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121301743) 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 15 ways as a sum of consecutive naturals, for example, 765308 + ... + 792425.

It is an arithmetic number, because the mean of its divisors is an integer number (1635620700).

Almost surely, 2^21121301747 is an apocalyptic number.

21121301747 is a deficient number, since it is larger than the sum of its proper divisors (5048629453).

21121301747 is a wasteful number, since it uses less digits than its factorization.

21121301747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1557902.

The product of its (nonzero) digits is 2352, while the sum is 29.

Adding to 21121301747 its reverse (74710312112), we get a palindrome (95831613859).

The spelling of 21121301747 in words is "twenty-one billion, one hundred twenty-one million, three hundred one thousand, seven hundred forty-seven".