21697710029 has 4 divisors (see below), whose sum is σ = 21889725276. Its totient is φ = 21505694784.

The previous prime is 21697710017. The next prime is 21697710049. The reversal of 21697710029 is 92001779612.

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 5346973129 + 16350736900 = 73123^2 + 127870^2 .

It is a cyclic number.

It is not a de Polignac number, because 21697710029 - 2²⁰ = 21696661453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21697710049) 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 3 ways as a sum of consecutive naturals, for example, 96007454 + ... + 96007679.

It is an arithmetic number, because the mean of its divisors is an integer number (5472431319).

Almost surely, 2^21697710029 is an apocalyptic number.

It is an amenable number.

21697710029 is a deficient number, since it is larger than the sum of its proper divisors (192015247).

21697710029 is a wasteful number, since it uses less digits than its factorization.

21697710029 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192015246.

The product of its (nonzero) digits is 95256, while the sum is 44.

The spelling of 21697710029 in words is "twenty-one billion, six hundred ninety-seven million, seven hundred ten thousand, twenty-nine".