68421511 has 2 divisors, whose sum is σ = 68421512. Its totient is φ = 68421510.

The previous prime is 68421467. The next prime is 68421517. The reversal of 68421511 is 11512486.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 68421511 - 2¹⁵ = 68388743 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 68421511.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68421517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34210755 + 34210756.

It is an arithmetic number, because the mean of its divisors is an integer number (34210756).

Almost surely, 2^68421511 is an apocalyptic number.

68421511 is a deficient number, since it is larger than the sum of its proper divisors (1).

68421511 is an equidigital number, since it uses as much as digits as its factorization.

68421511 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1920, while the sum is 28.

The square root of 68421511 is about 8271.7296256587. The cubic root of 68421511 is about 409.0071375659.

Adding to 68421511 its reverse (11512486), we get a palindrome (79933997).

The spelling of 68421511 in words is "sixty-eight million, four hundred twenty-one thousand, five hundred eleven".