1023113121721 has 2 divisors, whose sum is σ = 1023113121722. Its totient is φ = 1023113121720.

The previous prime is 1023113121713. The next prime is 1023113121749. The reversal of 1023113121721 is 1271213113201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 526003518121 + 497109603600 = 725261^2 + 705060^2 .

It is a cyclic number.

It is not a de Polignac number, because 1023113121721 - 2³ = 1023113121713 is a prime.

It is not a weakly prime, because it can be changed into another prime (1023113121781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 511556560860 + 511556560861.

It is an arithmetic number, because the mean of its divisors is an integer number (511556560861).

Almost surely, 2^{1023113121721} is an apocalyptic number.

It is an amenable number.

1023113121721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1023113121721 is an equidigital number, since it uses as much as digits as its factorization.

1023113121721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 25.

Adding to 1023113121721 its reverse (1271213113201), we get a palindrome (2294326234922).

The spelling of 1023113121721 in words is "one trillion, twenty-three billion, one hundred thirteen million, one hundred twenty-one thousand, seven hundred twenty-one".