206721672157 has 32 divisors (see below), whose sum is σ = 277871892480. Its totient is φ = 148521885120.

The previous prime is 206721672139. The next prime is 206721672163. The reversal of 206721672157 is 751276127602.

It is not a de Polignac number, because 206721672157 - 2³¹ = 204574188509 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206721678157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 766944 + ... + 1000822.

It is an arithmetic number, because the mean of its divisors is an integer number (8683496640).

Almost surely, 2^206721672157 is an apocalyptic number.

It is an amenable number.

206721672157 is a deficient number, since it is larger than the sum of its proper divisors (71150220323).

206721672157 is a wasteful number, since it uses less digits than its factorization.

206721672157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234793.

The product of its (nonzero) digits is 493920, while the sum is 46.

Adding to 206721672157 its reverse (751276127602), we get a palindrome (957997799759).

Subtracting 206721672157 from its reverse (751276127602), we obtain a palindrome (544554455445).

It can be divided in two parts, 206721 and 672157, that added together give a palindrome (878878).

The spelling of 206721672157 in words is "two hundred six billion, seven hundred twenty-one million, six hundred seventy-two thousand, one hundred fifty-seven".