206463640 has 128 divisors (see below), whose sum is σ = 526901760. Its totient is φ = 72382464.

The previous prime is 206463629. The next prime is 206463641. The reversal of 206463640 is 46364602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206463641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 672367 + ... + 672673.

It is an arithmetic number, because the mean of its divisors is an integer number (4116420).

Almost surely, 2^206463640 is an apocalyptic number.

206463640 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 206463640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263450880).

206463640 is an abundant number, since it is smaller than the sum of its proper divisors (320438120).

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

206463640 is a wasteful number, since it uses less digits than its factorization.

206463640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401 (or 397 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 31.

The square root of 206463640 is about 14368.8426813018. The cubic root of 206463640 is about 591.0368057029.

The spelling of 206463640 in words is "two hundred six million, four hundred sixty-three thousand, six hundred forty".