1240695121 has 2 divisors, whose sum is σ = 1240695122. Its totient is φ = 1240695120.

The previous prime is 1240695119. The next prime is 1240695149. The reversal of 1240695121 is 1215960421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 720170896 + 520524225 = 26836^2 + 22815^2 .

It is a cyclic number.

It is not a de Polignac number, because 1240695121 - 2¹ = 1240695119 is a prime.

Together with 1240695119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1240695191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 620347560 + 620347561.

It is an arithmetic number, because the mean of its divisors is an integer number (620347561).

Almost surely, 2^1240695121 is an apocalyptic number.

It is an amenable number.

1240695121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1240695121 is an equidigital number, since it uses as much as digits as its factorization.

1240695121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 1240695121 is about 35223.5023954178. The cubic root of 1240695121 is about 1074.5377846331.

The spelling of 1240695121 in words is "one billion, two hundred forty million, six hundred ninety-five thousand, one hundred twenty-one".