68611515844 has 9 divisors (see below), whose sum is σ = 120071069517. Its totient is φ = 34305495984.

The previous prime is 68611515829. The next prime is 68611515851. The reversal of 68611515844 is 44851511686.

The square root of 68611515844 is 261938.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 65772757444 + 2838758400 = 256462^2 + 53280^2 .

It is a super-2 number, since 2×68611515844² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 458392 + ... + 589360.

Almost surely, 2^68611515844 is an apocalyptic number.

68611515844 is the 261938-th square number.

It is an amenable number.

68611515844 is a deficient number, since it is larger than the sum of its proper divisors (51459553673).

68611515844 is an frugal number, since it uses more digits than its factorization.

68611515844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261942 (or 130971 counting only the distinct ones).

The product of its digits is 921600, while the sum is 49.

Multiplying 68611515844 by its sum of digits (49), we get a square (3361964276356 = 1833566²).

The spelling of 68611515844 in words is "sixty-eight billion, six hundred eleven million, five hundred fifteen thousand, eight hundred forty-four".