204420002343521 has 4 divisors (see below), whose sum is σ = 205549394621844. Its totient is φ = 203290610065200.

The previous prime is 204420002343463. The next prime is 204420002343643. The reversal of 204420002343521 is 125343200024402.

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 37580516787025 + 166839485556496 = 6130295^2 + 12916636^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-204420002343521 is a prime.

It is a super-2 number, since 2×204420002343521² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (204420002348521) 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, 564696138890 + ... + 564696139251.

It is an arithmetic number, because the mean of its divisors is an integer number (51387348655461).

Almost surely, 2^{204420002343521} is an apocalyptic number.

It is an amenable number.

204420002343521 is a deficient number, since it is larger than the sum of its proper divisors (1129392278323).

204420002343521 is a wasteful number, since it uses less digits than its factorization.

204420002343521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1129392278322.

The product of its (nonzero) digits is 46080, while the sum is 32.

Adding to 204420002343521 its reverse (125343200024402), we get a palindrome (329763202367923).

The spelling of 204420002343521 in words is "two hundred four trillion, four hundred twenty billion, two million, three hundred forty-three thousand, five hundred twenty-one".