205640025 has 12 divisors (see below), whose sum is σ = 339991632. Its totient is φ = 109674640.

The previous prime is 205640023. The next prime is 205640027. The reversal of 205640025 is 520046502.

It is an interprime number because it is at equal distance from previous prime (205640023) and next prime (205640027).

It is not a de Polignac number, because 205640025 - 2¹ = 205640023 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 205639977 and 205640004.

It is not an unprimeable number, because it can be changed into a prime (205640023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1370859 + ... + 1371008.

It is an arithmetic number, because the mean of its divisors is an integer number (28332636).

Almost surely, 2^205640025 is an apocalyptic number.

205640025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

205640025 is a deficient number, since it is larger than the sum of its proper divisors (134351607).

205640025 is a wasteful number, since it uses less digits than its factorization.

205640025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2741880 (or 2741875 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 205640025 is about 14340.1542878729. The cubic root of 205640025 is about 590.2498463041.

Adding to 205640025 its reverse (520046502), we get a palindrome (725686527).

The spelling of 205640025 in words is "two hundred five million, six hundred forty thousand, twenty-five".