206531506422551 has 16 divisors (see below), whose sum is σ = 219263343012000. Its totient is φ = 193864466976768.

The previous prime is 206531506422497. The next prime is 206531506422559. The reversal of 206531506422551 is 155224605135602.

It is not a de Polignac number, because 206531506422551 - 2⁴² = 202133459911447 is a prime.

It is a super-2 number, since 2×206531506422551² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 206531506422496 and 206531506422505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206531506422559) 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, 248884775 + ... + 249713223.

It is an arithmetic number, because the mean of its divisors is an integer number (13703958938250).

Almost surely, 2^{206531506422551} is an apocalyptic number.

206531506422551 is a deficient number, since it is larger than the sum of its proper divisors (12731836589449).

206531506422551 is a wasteful number, since it uses less digits than its factorization.

206531506422551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 867538.

The product of its (nonzero) digits is 2160000, while the sum is 47.

The spelling of 206531506422551 in words is "two hundred six trillion, five hundred thirty-one billion, five hundred six million, four hundred twenty-two thousand, five hundred fifty-one".