205657210000 has 400 divisors, whose sum is σ = 556887089088. Its totient is φ = 72928000000.

The previous prime is 205657209983. The next prime is 205657210009. The reversal of 205657210000 is 12756502.

It is a tau number, because it is divible by the number of its divisors (400).

It is not an unprimeable number, because it can be changed into a prime (205657210009) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1188769914 + ... + 1188770086.

Almost surely, 2^205657210000 is an apocalyptic number.

205657210000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 205657210000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (278443544544).

205657210000 is an abundant number, since it is smaller than the sum of its proper divisors (351229879088).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

205657210000 is a wasteful number, since it uses less digits than its factorization.

205657210000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420 (or 399 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 28.

Adding to 205657210000 its reverse (12756502), we get a palindrome (205669966502).

The spelling of 205657210000 in words is "two hundred five billion, six hundred fifty-seven million, two hundred ten thousand".