21135053641 has 27 divisors (see below), whose sum is σ = 23436915957. Its totient is φ = 19050464160.

The previous prime is 21135053561. The next prime is 21135053663. The reversal of 21135053641 is 14635053112.

The square root of 21135053641 is 145379.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 548543241 + 20586510400 = 23421^2 + 143480^2 .

It is not a de Polignac number, because 21135053641 - 2³³ = 12545119049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21135057641) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 100166026 + ... + 100166236.

Almost surely, 2^21135053641 is an apocalyptic number.

21135053641 is the 145379-th square number.

21135053641 is the 72690-th centered octagonal number.

It is an amenable number.

21135053641 is a deficient number, since it is larger than the sum of its proper divisors (2301862316).

21135053641 is an frugal number, since it uses more digits than its factorization.

21135053641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 554 (or 277 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 31.

The spelling of 21135053641 in words is "twenty-one billion, one hundred thirty-five million, fifty-three thousand, six hundred forty-one".