68750021 has 2 divisors, whose sum is σ = 68750022. Its totient is φ = 68750020.

The previous prime is 68749969. The next prime is 68750029. The reversal of 68750021 is 12005786.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68724100 + 25921 = 8290^2 + 161^2 .

It is a cyclic number.

It is not a de Polignac number, because 68750021 - 2¹⁸ = 68487877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68750029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34375010 + 34375011.

It is an arithmetic number, because the mean of its divisors is an integer number (34375011).

Almost surely, 2^68750021 is an apocalyptic number.

It is an amenable number.

68750021 is a deficient number, since it is larger than the sum of its proper divisors (1).

68750021 is an equidigital number, since it uses as much as digits as its factorization.

68750021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 68750021 is about 8291.5632422361. The cubic root of 68750021 is about 409.6606770112.

The spelling of 68750021 in words is "sixty-eight million, seven hundred fifty thousand, twenty-one".