6781750121 has 2 divisors, whose sum is σ = 6781750122. Its totient is φ = 6781750120.

The previous prime is 6781750111. The next prime is 6781750159. The reversal of 6781750121 is 1210571876.

It is a happy number.

It is an a-pointer prime, because the next prime (6781750159) can be obtained adding 6781750121 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5452345600 + 1329404521 = 73840^2 + 36461^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6781750121 is a prime.

It is not a weakly prime, because it can be changed into another prime (6781750111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3390875060 + 3390875061.

It is an arithmetic number, because the mean of its divisors is an integer number (3390875061).

Almost surely, 2^6781750121 is an apocalyptic number.

It is an amenable number.

6781750121 is a deficient number, since it is larger than the sum of its proper divisors (1).

6781750121 is an equidigital number, since it uses as much as digits as its factorization.

6781750121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23520, while the sum is 38.

The square root of 6781750121 is about 82351.3820224045. The cubic root of 6781750121 is about 1892.8400999338.

The spelling of 6781750121 in words is "six billion, seven hundred eighty-one million, seven hundred fifty thousand, one hundred twenty-one".