68456012881 has 3 divisors (see below), whose sum is σ = 68456274523. Its totient is φ = 68455751240.

The previous prime is 68456012861. The next prime is 68456012887. The reversal of 68456012881 is 18821065486.

The square root of 68456012881 is 261641.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 53080012881 + 15376000000 = 230391^2 + 124000^2 .

It is not a de Polignac number, because 68456012881 - 2³¹ = 66308529233 is a prime.

It is a super-2 number, since 2×68456012881² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68456012887) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 130821 + ... + 392461.

Almost surely, 2^68456012881 is an apocalyptic number.

68456012881 is the 261641-st square number.

68456012881 is the 130821-st centered octagonal number.

It is an amenable number.

68456012881 is a deficient number, since it is larger than the sum of its proper divisors (261642).

68456012881 is an frugal number, since it uses more digits than its factorization.

68456012881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523282 (or 261641 counting only the distinct ones).

The product of its (nonzero) digits is 737280, while the sum is 49.

Multiplying 68456012881 by its sum of digits (49), we get a square (3354344631169 = 1831487²).

The spelling of 68456012881 in words is "sixty-eight billion, four hundred fifty-six million, twelve thousand, eight hundred eighty-one".