68880821 has 4 divisors (see below), whose sum is σ = 72932652. Its totient is φ = 64828992.

The previous prime is 68880751. The next prime is 68880839. The reversal of 68880821 is 12808886.

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

It can be written as a sum of positive squares in 2 ways, for example, as 39828721 + 29052100 = 6311^2 + 5390^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68880821 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68880881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2025890 + ... + 2025923.

It is an arithmetic number, because the mean of its divisors is an integer number (18233163).

Almost surely, 2^68880821 is an apocalyptic number.

It is an amenable number.

68880821 is a deficient number, since it is larger than the sum of its proper divisors (4051831).

68880821 is a wasteful number, since it uses less digits than its factorization.

68880821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4051830.

The product of its (nonzero) digits is 49152, while the sum is 41.

The square root of 68880821 is about 8299.4470297725. The cubic root of 68880821 is about 409.9203116988.

The spelling of 68880821 in words is "sixty-eight million, eight hundred eighty thousand, eight hundred twenty-one".