208442405 has 4 divisors (see below), whose sum is σ = 250130892. Its totient is φ = 166753920.

The previous prime is 208442387. The next prime is 208442411. The reversal of 208442405 is 504244802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 504244802 = 2 ⋅252122401.

It can be written as a sum of positive squares in 2 ways, for example, as 67141636 + 141300769 = 8194^2 + 11887^2 .

It is not a de Polignac number, because 208442405 - 2⁶ = 208442341 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20844236 + ... + 20844245.

It is an arithmetic number, because the mean of its divisors is an integer number (62532723).

Almost surely, 2^208442405 is an apocalyptic number.

It is an amenable number.

208442405 is a deficient number, since it is larger than the sum of its proper divisors (41688487).

208442405 is an equidigital number, since it uses as much as digits as its factorization.

208442405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41688486.

The product of its (nonzero) digits is 10240, while the sum is 29.

The square root of 208442405 is about 14437.5345887032. The cubic root of 208442405 is about 592.9189877074.

The spelling of 208442405 in words is "two hundred eight million, four hundred forty-two thousand, four hundred five".