206154056761 has 4 divisors (see below), whose sum is σ = 209533631524. Its totient is φ = 202774482000.

The previous prime is 206154056749. The next prime is 206154056789. The reversal of 206154056761 is 167650451602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 51847290000 + 154306766761 = 227700^2 + 392819^2 .

It is a cyclic number.

It is not a de Polignac number, because 206154056761 - 2⁵ = 206154056729 is a prime.

It is a super-2 number, since 2×206154056761² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206155056761) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1689787290 + ... + 1689787411.

It is an arithmetic number, because the mean of its divisors is an integer number (52383407881).

Almost surely, 2^206154056761 is an apocalyptic number.

It is an amenable number.

206154056761 is a deficient number, since it is larger than the sum of its proper divisors (3379574763).

206154056761 is an equidigital number, since it uses as much as digits as its factorization.

206154056761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3379574762.

The product of its (nonzero) digits is 302400, while the sum is 43.

The spelling of 206154056761 in words is "two hundred six billion, one hundred fifty-four million, fifty-six thousand, seven hundred sixty-one".