206919540 has 72 divisors (see below), whose sum is σ = 644640360. Its totient is φ = 53685504.

The previous prime is 206919539. The next prime is 206919547. The reversal of 206919540 is 45919602.

206919540 is a `hidden beast` number, since 20 + 6 + 91 + 9 + 540 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 62631396 + 144288144 = 7914^2 + 12012^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 206919495 and 206919504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206919547) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8875 + ... + 22194.

Almost surely, 2^206919540 is an apocalyptic number.

206919540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

206919540 is an abundant number, since it is smaller than the sum of its proper divisors (437720820).

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

206919540 is a wasteful number, since it uses less digits than its factorization.

206919540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31121 (or 31116 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 206919540 is about 14384.6981198772. The cubic root of 206919540 is about 591.4715159703.

It can be divided in two parts, 2069 and 19540, that added together give a square (21609 = 147²).

The spelling of 206919540 in words is "two hundred six million, nine hundred nineteen thousand, five hundred forty".