205651520 has 56 divisors (see below), whose sum is σ = 505529088. Its totient is φ = 79603200.

The previous prime is 205651519. The next prime is 205651559. The reversal of 205651520 is 25156502.

It is a self number, because there is not a number n which added to its sum of digits gives 205651520.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 446 + ... + 20285.

Almost surely, 2^205651520 is an apocalyptic number.

205651520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 205651520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (252764544).

205651520 is an abundant number, since it is smaller than the sum of its proper divisors (299877568).

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

205651520 is a wasteful number, since it uses less digits than its factorization.

205651520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20779 (or 20769 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 26.

The square root of 205651520 is about 14340.5550799124. Note that the first 3 decimals coincide. The cubic root of 205651520 is about 590.2608441559.

The spelling of 205651520 in words is "two hundred five million, six hundred fifty-one thousand, five hundred twenty".