68621621 has 2 divisors, whose sum is σ = 68621622. Its totient is φ = 68621620.

The previous prime is 68621563. The next prime is 68621647. The reversal of 68621621 is 12612686.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63377521 + 5244100 = 7961^2 + 2290^2 .

It is a cyclic number.

It is not a de Polignac number, because 68621621 - 2¹⁴ = 68605237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68621671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34310810 + 34310811.

It is an arithmetic number, because the mean of its divisors is an integer number (34310811).

Almost surely, 2^68621621 is an apocalyptic number.

It is an amenable number.

68621621 is a deficient number, since it is larger than the sum of its proper divisors (1).

68621621 is an equidigital number, since it uses as much as digits as its factorization.

68621621 is an evil number, because the sum of its binary digits is even.

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

The square root of 68621621 is about 8283.8168135226. The cubic root of 68621621 is about 409.4054857626.

The spelling of 68621621 in words is "sixty-eight million, six hundred twenty-one thousand, six hundred twenty-one".