21055540653 has 32 divisors (see below), whose sum is σ = 35734809600. Its totient is φ = 12002977008.

The previous prime is 21055540651. The next prime is 21055540657. The reversal of 21055540653 is 35604555012.

21055540653 is a `hidden beast` number, since 2 + 1 + 0 + 55 + 540 + 65 + 3 = 666.

It is not a de Polignac number, because 21055540653 - 2¹ = 21055540651 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21055540651) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 53751 + ... + 212132.

It is an arithmetic number, because the mean of its divisors is an integer number (1116712800).

Almost surely, 2^21055540653 is an apocalyptic number.

It is an amenable number.

21055540653 is a deficient number, since it is larger than the sum of its proper divisors (14679268947).

21055540653 is a wasteful number, since it uses less digits than its factorization.

21055540653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266318 (or 266312 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 36.

The spelling of 21055540653 in words is "twenty-one billion, fifty-five million, five hundred forty thousand, six hundred fifty-three".