212605561 has 9 divisors (see below), whose sum is σ = 247435461. Its totient is φ = 182145852.

The previous prime is 212605559. The next prime is 212605577. The reversal of 212605561 is 165506212.

The square root of 212605561 is 14581.

It is a perfect power (a square), and thus also a powerful number.

212605561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 212605561 - 2¹ = 212605559 is a prime.

It is a super-2 number, since 2×212605561² = 90402249136249442, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (212605361) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 101026 + ... + 103108.

It is an arithmetic number, because the mean of its divisors is an integer number (27492829).

Almost surely, 2^212605561 is an apocalyptic number.

212605561 is the 14581-st square number.

212605561 is the 7291-st centered octagonal number.

It is an amenable number.

212605561 is a deficient number, since it is larger than the sum of its proper divisors (34829900).

212605561 is an frugal number, since it uses more digits than its factorization.

212605561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4180 (or 2090 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 28.

The cubic root of 212605561 is about 596.8403915900.

Multiplying 212605561 by its product of nonzero digits (3600), we get a square (765380019600 = 874860²).

The spelling of 212605561 in words is "two hundred twelve million, six hundred five thousand, five hundred sixty-one".