208451603421 has 6 divisors (see below), whose sum is σ = 301096760510. Its totient is φ = 138967735608.

The previous prime is 208451603417. The next prime is 208451603431. The reversal of 208451603421 is 124306154802.

It is a happy number.

208451603421 is a `hidden beast` number, since 2 + 0 + 8 + 4 + 5 + 1 + 603 + 42 + 1 = 666.

208451603421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 194560388100 + 13891215321 = 441090^2 + 117861^2 .

It is not a de Polignac number, because 208451603421 - 2² = 208451603417 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 (208451603431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11580644626 + ... + 11580644643.

Almost surely, 2^208451603421 is an apocalyptic number.

It is an amenable number.

208451603421 is a deficient number, since it is larger than the sum of its proper divisors (92645157089).

208451603421 is a wasteful number, since it uses less digits than its factorization.

208451603421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23161289275 (or 23161289272 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The spelling of 208451603421 in words is "two hundred eight billion, four hundred fifty-one million, six hundred three thousand, four hundred twenty-one".