205057617621 has 8 divisors (see below), whose sum is σ = 274198083744. Its totient is φ = 136311114960.

The previous prime is 205057617607. The next prime is 205057617703. The reversal of 205057617621 is 126716750502.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 205057617621 - 2⁷ = 205057617493 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205057610621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 98489650 + ... + 98491731.

It is an arithmetic number, because the mean of its divisors is an integer number (34274760468).

Almost surely, 2^205057617621 is an apocalyptic number.

It is an amenable number.

205057617621 is a deficient number, since it is larger than the sum of its proper divisors (69140466123).

205057617621 is a wasteful number, since it uses less digits than its factorization.

205057617621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196981731.

The product of its (nonzero) digits is 176400, while the sum is 42.

The spelling of 205057617621 in words is "two hundred five billion, fifty-seven million, six hundred seventeen thousand, six hundred twenty-one".