21534535097 has 4 divisors (see below), whose sum is σ = 21581657076. Its totient is φ = 21487413120.

The previous prime is 21534535073. The next prime is 21534535123. The reversal of 21534535097 is 79053543512.

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 19896795136 + 1637739961 = 141056^2 + 40469^2 .

It is a cyclic number.

It is not a de Polignac number, because 21534535097 - 2²⁴ = 21517757881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21534535067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23560304 + ... + 23561217.

It is an arithmetic number, because the mean of its divisors is an integer number (5395414269).

Almost surely, 2^21534535097 is an apocalyptic number.

It is an amenable number.

21534535097 is a deficient number, since it is larger than the sum of its proper divisors (47121979).

21534535097 is an equidigital number, since it uses as much as digits as its factorization.

21534535097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47121978.

The product of its (nonzero) digits is 567000, while the sum is 44.

The spelling of 21534535097 in words is "twenty-one billion, five hundred thirty-four million, five hundred thirty-five thousand, ninety-seven".