68261621 has 4 divisors (see below), whose sum is σ = 70615500. Its totient is φ = 65907744.

The previous prime is 68261617. The next prime is 68261663. The reversal of 68261621 is 12616286.

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 53129521 + 15132100 = 7289^2 + 3890^2 .

It is a cyclic number.

It is not a de Polignac number, because 68261621 - 2² = 68261617 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 (68261671) 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 3 ways as a sum of consecutive naturals, for example, 1176896 + ... + 1176953.

It is an arithmetic number, because the mean of its divisors is an integer number (17653875).

Almost surely, 2^68261621 is an apocalyptic number.

It is an amenable number.

68261621 is a deficient number, since it is larger than the sum of its proper divisors (2353879).

68261621 is a wasteful number, since it uses less digits than its factorization.

68261621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2353878.

The product of its digits is 6912, while the sum is 32.

The square root of 68261621 is about 8262.0591259080. The cubic root of 68261621 is about 408.6882945755.

The spelling of 68261621 in words is "sixty-eight million, two hundred sixty-one thousand, six hundred twenty-one".