205212120156 has 18 divisors (see below), whose sum is σ = 518730637152. Its totient is φ = 68404040040.

The previous prime is 205212120149. The next prime is 205212120163. The reversal of 205212120156 is 651021212502.

205212120156 is a `hidden beast` number, since 2 + 0 + 521 + 2 + 120 + 15 + 6 = 666.

205212120156 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (205212120149) and next prime (205212120163).

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×205212120156² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2850168300 + ... + 2850168371.

Almost surely, 2^205212120156 is an apocalyptic number.

It is an amenable number.

205212120156 is an abundant number, since it is smaller than the sum of its proper divisors (313518516996).

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

205212120156 is a wasteful number, since it uses less digits than its factorization.

205212120156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5700336681 (or 5700336676 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

Adding to 205212120156 its reverse (651021212502), we get a palindrome (856233332658).

The spelling of 205212120156 in words is "two hundred five billion, two hundred twelve million, one hundred twenty thousand, one hundred fifty-six".