205712649 has 16 divisors (see below), whose sum is σ = 305094400. Its totient is φ = 136991088.

The previous prime is 205712641. The next prime is 205712657. The reversal of 205712649 is 946217502.

205712649 is a `hidden beast` number, since 2 + 0 + 5 + 7 + 1 + 2 + 649 = 666.

It is an interprime number because it is at equal distance from previous prime (205712641) and next prime (205712657).

It is not a de Polignac number, because 205712649 - 2³ = 205712641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205712641) 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, 24387 + ... + 31719.

It is an arithmetic number, because the mean of its divisors is an integer number (19068400).

Almost surely, 2^205712649 is an apocalyptic number.

It is an amenable number.

205712649 is a deficient number, since it is larger than the sum of its proper divisors (99381751).

205712649 is a wasteful number, since it uses less digits than its factorization.

205712649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8381 (or 8375 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 205712649 is about 14342.6862546735. The cubic root of 205712649 is about 590.3193224994.

It can be divided in two parts, 20571 and 2649, that added together give a triangular number (23220 = T₂₁₅).

The spelling of 205712649 in words is "two hundred five million, seven hundred twelve thousand, six hundred forty-nine".