209616925421 has 4 divisors (see below), whose sum is σ = 220649395200. Its totient is φ = 198584455644.

The previous prime is 209616925391. The next prime is 209616925451. The reversal of 209616925421 is 124529616902.

209616925421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 an interprime number because it is at equal distance from previous prime (209616925391) and next prime (209616925451).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209616925421 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 (209616925451) 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 3 ways as a sum of consecutive naturals, for example, 5516234861 + ... + 5516234898.

It is an arithmetic number, because the mean of its divisors is an integer number (55162348800).

Almost surely, 2^209616925421 is an apocalyptic number.

It is an amenable number.

209616925421 is a deficient number, since it is larger than the sum of its proper divisors (11032469779).

209616925421 is a wasteful number, since it uses less digits than its factorization.

209616925421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11032469778.

The product of its (nonzero) digits is 466560, while the sum is 47.

The spelling of 209616925421 in words is "two hundred nine billion, six hundred sixteen million, nine hundred twenty-five thousand, four hundred twenty-one".