21647759253 has 16 divisors (see below), whose sum is σ = 29866043520. Its totient is φ = 13930892864.

The previous prime is 21647759227. The next prime is 21647759261. The reversal of 21647759253 is 35295774612.

It is not a de Polignac number, because 21647759253 - 2¹⁰ = 21647758229 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21647759196 and 21647759205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21647757253) 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 15 ways as a sum of consecutive naturals, for example, 371575 + ... + 425867.

It is an arithmetic number, because the mean of its divisors is an integer number (1866627720).

Almost surely, 2^21647759253 is an apocalyptic number.

It is an amenable number.

21647759253 is a deficient number, since it is larger than the sum of its proper divisors (8218284267).

21647759253 is a wasteful number, since it uses less digits than its factorization.

21647759253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58908.

The product of its digits is 3175200, while the sum is 51.

The spelling of 21647759253 in words is "twenty-one billion, six hundred forty-seven million, seven hundred fifty-nine thousand, two hundred fifty-three".