205506401 has 4 divisors (see below), whose sum is σ = 205592832. Its totient is φ = 205419972.

The previous prime is 205506397. The next prime is 205506437. The reversal of 205506401 is 104605502.

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, and also an emirpimes, since its reverse is a distinct semiprime: 104605502 = 2 ⋅52302751.

It is a cyclic number.

It is not a de Polignac number, because 205506401 - 2² = 205506397 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205500401) 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, 39545 + ... + 44438.

It is an arithmetic number, because the mean of its divisors is an integer number (51398208).

Almost surely, 2^205506401 is an apocalyptic number.

It is an amenable number.

205506401 is a deficient number, since it is larger than the sum of its proper divisors (86431).

205506401 is an equidigital number, since it uses as much as digits as its factorization.

205506401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86430.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 205506401 is about 14335.4944456060. The cubic root of 205506401 is about 590.1219713357.

The spelling of 205506401 in words is "two hundred five million, five hundred six thousand, four hundred one".