201656640 has 112 divisors (see below), whose sum is σ = 668170368. Its totient is φ = 51431424.

The previous prime is 201656597. The next prime is 201656641. The reversal of 201656640 is 46656102.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 201656598 and 201656607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201656641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17514 + ... + 26646.

Almost surely, 2^201656640 is an apocalyptic number.

201656640 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 201656640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (334085184).

201656640 is an abundant number, since it is smaller than the sum of its proper divisors (466513728).

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

201656640 is a wasteful number, since it uses less digits than its factorization.

201656640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9176 (or 9166 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 201656640 is about 14200.5859034055. The cubic root of 201656640 is about 586.4137913843.

The spelling of 201656640 in words is "two hundred one million, six hundred fifty-six thousand, six hundred forty".