204501388681 has 4 divisors (see below), whose sum is σ = 204537582864. Its totient is φ = 204465194500.

The previous prime is 204501388649. The next prime is 204501388717. The reversal of 204501388681 is 186883105402.

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 204501388681 - 2⁵ = 204501388649 is a prime.

It is a super-2 number, since 2×204501388681² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (204501388081) 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, 18088615 + ... + 18099916.

It is an arithmetic number, because the mean of its divisors is an integer number (51134395716).

Almost surely, 2^204501388681 is an apocalyptic number.

It is an amenable number.

204501388681 is a deficient number, since it is larger than the sum of its proper divisors (36194183).

204501388681 is an equidigital number, since it uses as much as digits as its factorization.

204501388681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36194182.

The product of its (nonzero) digits is 368640, while the sum is 46.

The spelling of 204501388681 in words is "two hundred four billion, five hundred one million, three hundred eighty-eight thousand, six hundred eighty-one".