206581551 has 16 divisors (see below), whose sum is σ = 310176768. Its totient is φ = 121161600.

The previous prime is 206581541. The next prime is 206581559. The reversal of 206581551 is 155185602.

206581551 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 206581551 - 2¹⁷ = 206450479 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206581559) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 99946 + ... + 101991.

It is an arithmetic number, because the mean of its divisors is an integer number (19386048).

Almost surely, 2^206581551 is an apocalyptic number.

206581551 is a deficient number, since it is larger than the sum of its proper divisors (103595217).

206581551 is a wasteful number, since it uses less digits than its factorization.

206581551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201982.

The product of its (nonzero) digits is 12000, while the sum is 33.

The square root of 206581551 is about 14372.9451053011. The cubic root of 206581551 is about 591.1492976304.

The spelling of 206581551 in words is "two hundred six million, five hundred eighty-one thousand, five hundred fifty-one".