204245890581 has 4 divisors (see below), whose sum is σ = 272327854112. Its totient is φ = 136163927052.

The previous prime is 204245890579. The next prime is 204245890613. The reversal of 204245890581 is 185098542402.

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 not a de Polignac number, because 204245890581 - 2¹ = 204245890579 is a prime.

It is a super-2 number, since 2×204245890581² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 204245890581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204245890181) 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, 34040981761 + ... + 34040981766.

It is an arithmetic number, because the mean of its divisors is an integer number (68081963528).

Almost surely, 2^204245890581 is an apocalyptic number.

It is an amenable number.

204245890581 is a deficient number, since it is larger than the sum of its proper divisors (68081963531).

204245890581 is an equidigital number, since it uses as much as digits as its factorization.

204245890581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68081963530.

The product of its (nonzero) digits is 921600, while the sum is 48.

The spelling of 204245890581 in words is "two hundred four billion, two hundred forty-five million, eight hundred ninety thousand, five hundred eighty-one".