21513275749 has 32 divisors (see below), whose sum is σ = 26256384000. Its totient is φ = 17217645120.

The previous prime is 21513275743. The next prime is 21513275761. The reversal of 21513275749 is 94757231512.

It is a cyclic number.

It is not a de Polignac number, because 21513275749 - 2⁵ = 21513275717 is a prime.

It is a super-2 number, since 2×21513275749² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21513275699 and 21513275708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21513275743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2591884 + ... + 2600170.

It is an arithmetic number, because the mean of its divisors is an integer number (820512000).

Almost surely, 2^21513275749 is an apocalyptic number.

It is an amenable number.

21513275749 is a deficient number, since it is larger than the sum of its proper divisors (4743108251).

21513275749 is a wasteful number, since it uses less digits than its factorization.

21513275749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8593.

The product of its digits is 529200, while the sum is 46.

The spelling of 21513275749 in words is "twenty-one billion, five hundred thirteen million, two hundred seventy-five thousand, seven hundred forty-nine".