68928821 has 8 divisors (see below), whose sum is σ = 74380824. Its totient is φ = 63498240.

The previous prime is 68928803. The next prime is 68928823. The reversal of 68928821 is 12882986.

It can be written as a sum of positive squares in 4 ways, for example, as 1918225 + 67010596 = 1385^2 + 8186^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 68928821 - 2¹⁰ = 68927797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68928823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1685 + ... + 11861.

It is an arithmetic number, because the mean of its divisors is an integer number (9297603).

Almost surely, 2^68928821 is an apocalyptic number.

It is an amenable number.

68928821 is a deficient number, since it is larger than the sum of its proper divisors (5452003).

68928821 is a wasteful number, since it uses less digits than its factorization.

68928821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10711.

The product of its digits is 110592, while the sum is 44.

The square root of 68928821 is about 8302.3382850857. The cubic root of 68928821 is about 410.0155080392.

The spelling of 68928821 in words is "sixty-eight million, nine hundred twenty-eight thousand, eight hundred twenty-one".