68521654731815 has 4 divisors (see below), whose sum is σ = 82225985678184. Its totient is φ = 54817323785448.

The previous prime is 68521654731781. The next prime is 68521654731841. The reversal of 68521654731815 is 51813745612586.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 68521654731815 - 2³² = 68517359764519 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6852165473177 + ... + 6852165473186.

It is an arithmetic number, because the mean of its divisors is an integer number (20556496419546).

Almost surely, 2^{68521654731815} is an apocalyptic number.

68521654731815 is a deficient number, since it is larger than the sum of its proper divisors (13704330946369).

68521654731815 is a wasteful number, since it uses less digits than its factorization.

68521654731815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13704330946368.

The product of its digits is 48384000, while the sum is 62.

The spelling of 68521654731815 in words is "sixty-eight trillion, five hundred twenty-one billion, six hundred fifty-four million, seven hundred thirty-one thousand, eight hundred fifteen".