206917920 has 144 divisors (see below), whose sum is σ = 770357952. Its totient is φ = 50158080.

The previous prime is 206917873. The next prime is 206917943. The reversal of 206917920 is 29719602.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9309 + ... + 22371.

It is an arithmetic number, because the mean of its divisors is an integer number (5349708).

Almost surely, 2^206917920 is an apocalyptic number.

206917920 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 206917920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (385178976).

206917920 is an abundant number, since it is smaller than the sum of its proper divisors (563440032).

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

206917920 is a wasteful number, since it uses less digits than its factorization.

206917920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13095 (or 13084 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 206917920 is about 14384.6418099305. The cubic root of 206917920 is about 591.4699723971.

The spelling of 206917920 in words is "two hundred six million, nine hundred seventeen thousand, nine hundred twenty".