21706735653 has 24 divisors (see below), whose sum is σ = 31469124960. Its totient is φ = 14418188640.

The previous prime is 21706735627. The next prime is 21706735663. The reversal of 21706735653 is 35653760712.

21706735653 is a `hidden beast` number, since 2 + 17 + 0 + 6 + 73 + 565 + 3 = 666.

It is not a de Polignac number, because 21706735653 - 2⁵ = 21706735621 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21706735599 and 21706735608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21706735663) 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 23 ways as a sum of consecutive naturals, for example, 3816750 + ... + 3822432.

It is an arithmetic number, because the mean of its divisors is an integer number (1311213540).

Almost surely, 2^21706735653 is an apocalyptic number.

It is an amenable number.

21706735653 is a deficient number, since it is larger than the sum of its proper divisors (9762389307).

21706735653 is a wasteful number, since it uses less digits than its factorization.

21706735653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7169 (or 7166 counting only the distinct ones).

The product of its (nonzero) digits is 793800, while the sum is 45.

The spelling of 21706735653 in words is "twenty-one billion, seven hundred six million, seven hundred thirty-five thousand, six hundred fifty-three".