205651820640 has 768 divisors, whose sum is σ = 811045509120. Its totient is φ = 42732748800.

The previous prime is 205651820629. The next prime is 205651820719. The reversal of 205651820640 is 46028156502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 248071746 + ... + 248072574.

It is an arithmetic number, because the mean of its divisors is an integer number (1056048840).

Almost surely, 2^205651820640 is an apocalyptic number.

205651820640 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 205651820640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (405522754560).

205651820640 is an abundant number, since it is smaller than the sum of its proper divisors (605393688480).

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

205651820640 is a wasteful number, since it uses less digits than its factorization.

205651820640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1015 (or 1007 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 39.

The spelling of 205651820640 in words is "two hundred five billion, six hundred fifty-one million, eight hundred twenty thousand, six hundred forty".