208406957 has 4 divisors (see below), whose sum is σ = 227353056. Its totient is φ = 189460860.

The previous prime is 208406951. The next prime is 208406959. The reversal of 208406957 is 759604802.

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 208406957 - 2²⁴ = 191629741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208406951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9473033 + ... + 9473054.

It is an arithmetic number, because the mean of its divisors is an integer number (56838264).

Almost surely, 2^208406957 is an apocalyptic number.

It is an amenable number.

208406957 is a deficient number, since it is larger than the sum of its proper divisors (18946099).

208406957 is a wasteful number, since it uses less digits than its factorization.

208406957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18946098.

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 208406957 is about 14436.3069030829. The cubic root of 208406957 is about 592.8853749311.

The spelling of 208406957 in words is "two hundred eight million, four hundred six thousand, nine hundred fifty-seven".