205672221557 has 16 divisors (see below), whose sum is σ = 227018417472. Its totient is φ = 184773189120.

The previous prime is 205672221553. The next prime is 205672221571. The reversal of 205672221557 is 755122276502.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 205672221557 - 2² = 205672221553 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205672221551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 579998 + ... + 864720.

It is an arithmetic number, because the mean of its divisors is an integer number (14188651092).

Almost surely, 2^205672221557 is an apocalyptic number.

It is an amenable number.

205672221557 is a deficient number, since it is larger than the sum of its proper divisors (21346195915).

205672221557 is a wasteful number, since it uses less digits than its factorization.

205672221557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285508.

The product of its (nonzero) digits is 588000, while the sum is 44.

Subtracting 205672221557 from its reverse (755122276502), we obtain a palindrome (549450054945).

The spelling of 205672221557 in words is "two hundred five billion, six hundred seventy-two million, two hundred twenty-one thousand, five hundred fifty-seven".