21240346653 has 12 divisors (see below), whose sum is σ = 31050146400. Its totient is φ = 13989625416.

The previous prime is 21240346637. The next prime is 21240346657. The reversal of 21240346653 is 35664304212.

21240346653 is a `hidden beast` number, since 21 + 240 + 346 + 6 + 53 = 666.

It is not a de Polignac number, because 21240346653 - 2⁴ = 21240346637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21240346657) 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 11 ways as a sum of consecutive naturals, for example, 14216353 + ... + 14217846.

It is an arithmetic number, because the mean of its divisors is an integer number (2587512200).

Almost surely, 2^21240346653 is an apocalyptic number.

It is an amenable number.

21240346653 is a deficient number, since it is larger than the sum of its proper divisors (9809799747).

21240346653 is a wasteful number, since it uses less digits than its factorization.

21240346653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28434288 (or 28434285 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The spelling of 21240346653 in words is "twenty-one billion, two hundred forty million, three hundred forty-six thousand, six hundred fifty-three".