21097530653 has 4 divisors (see below), whose sum is σ = 21825031740. Its totient is φ = 20370029568.

The previous prime is 21097530617. The next prime is 21097530691. The reversal of 21097530653 is 35603579012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4186348804 + 16911181849 = 64702^2 + 130043^2 .

It is a cyclic number.

It is not a de Polignac number, because 21097530653 - 2¹⁸ = 21097268509 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21097530653.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21097530613) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 363750500 + ... + 363750557.

It is an arithmetic number, because the mean of its divisors is an integer number (5456257935).

Almost surely, 2^21097530653 is an apocalyptic number.

It is an amenable number.

21097530653 is a deficient number, since it is larger than the sum of its proper divisors (727501087).

21097530653 is an equidigital number, since it uses as much as digits as its factorization.

21097530653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 727501086.

The product of its (nonzero) digits is 170100, while the sum is 41.

The spelling of 21097530653 in words is "twenty-one billion, ninety-seven million, five hundred thirty thousand, six hundred fifty-three".