206121645315 has 24 divisors (see below), whose sum is σ = 362309601888. Its totient is φ = 108383210880.

The previous prime is 206121645259. The next prime is 206121645361. The reversal of 206121645315 is 513546121602.

206121645315 is a `hidden beast` number, since 2 + 0 + 6 + 1 + 2 + 1 + 645 + 3 + 1 + 5 = 666.

It is not a de Polignac number, because 206121645315 - 2¹⁵ = 206121612547 is a prime.

It is a super-2 number, since 2×206121645315² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 206121645315.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32253714 + ... + 32260103.

It is an arithmetic number, because the mean of its divisors is an integer number (15096233412).

Almost surely, 2^206121645315 is an apocalyptic number.

206121645315 is a deficient number, since it is larger than the sum of its proper divisors (156187956573).

206121645315 is a wasteful number, since it uses less digits than its factorization.

206121645315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64513899 (or 64513896 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

Adding to 206121645315 its reverse (513546121602), we get a palindrome (719667766917).

The spelling of 206121645315 in words is "two hundred six billion, one hundred twenty-one million, six hundred forty-five thousand, three hundred fifteen".