21142817573 has 4 divisors (see below), whose sum is σ = 21440603808. Its totient is φ = 20845031340.

The previous prime is 21142817569. The next prime is 21142817581. The reversal of 21142817573 is 37571824112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21142817573 - 2² = 21142817569 is a prime.

It is a super-2 number, since 2×21142817573² (a number of 21 digits) contains 22 as substring.

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 21142817573.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21142817593) 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, 148893011 + ... + 148893152.

It is an arithmetic number, because the mean of its divisors is an integer number (5360150952).

Almost surely, 2^21142817573 is an apocalyptic number.

It is an amenable number.

21142817573 is a deficient number, since it is larger than the sum of its proper divisors (297786235).

21142817573 is an equidigital number, since it uses as much as digits as its factorization.

21142817573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297786234.

The product of its digits is 94080, while the sum is 41.

The spelling of 21142817573 in words is "twenty-one billion, one hundred forty-two million, eight hundred seventeen thousand, five hundred seventy-three".