21571352653 has 2 divisors, whose sum is σ = 21571352654. Its totient is φ = 21571352652.

The previous prime is 21571352639. The next prime is 21571352753. The reversal of 21571352653 is 35625317512.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18225540004 + 3345812649 = 135002^2 + 57843^2 .

It is a cyclic number.

It is not a de Polignac number, because 21571352653 - 2²⁵ = 21537798221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21571352633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10785676326 + 10785676327.

It is an arithmetic number, because the mean of its divisors is an integer number (10785676327).

Almost surely, 2^21571352653 is an apocalyptic number.

It is an amenable number.

21571352653 is a deficient number, since it is larger than the sum of its proper divisors (1).

21571352653 is an equidigital number, since it uses as much as digits as its factorization.

21571352653 is an evil number, because the sum of its binary digits is even.

The product of its digits is 189000, while the sum is 40.

The spelling of 21571352653 in words is "twenty-one billion, five hundred seventy-one million, three hundred fifty-two thousand, six hundred fifty-three".