206126721 has 32 divisors (see below), whose sum is σ = 316915200. Its totient is φ = 132312960.

The previous prime is 206126681. The next prime is 206126731. The reversal of 206126721 is 127621602.

206126721 is a `hidden beast` number, since 20 + 612 + 6 + 7 + 21 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-206126721 is a prime.

It is a super-2 number, since 2×206126721² = 84976450220423682, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (206126731) 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, 86275 + ... + 88631.

It is an arithmetic number, because the mean of its divisors is an integer number (9903600).

Almost surely, 2^206126721 is an apocalyptic number.

It is an amenable number.

206126721 is a deficient number, since it is larger than the sum of its proper divisors (110788479).

206126721 is a wasteful number, since it uses less digits than its factorization.

206126721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2486 (or 2480 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 206126721 is about 14357.1139509304. The cubic root of 206126721 is about 590.7151349463.

It can be divided in two parts, 2061 and 26721, that added together give a palindrome (28782).

The spelling of 206126721 in words is "two hundred six million, one hundred twenty-six thousand, seven hundred twenty-one".