1240646221 has 2 divisors, whose sum is σ = 1240646222. Its totient is φ = 1240646220.

The previous prime is 1240646203. The next prime is 1240646233. The reversal of 1240646221 is 1226460421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 869660100 + 370986121 = 29490^2 + 19261^2 .

It is a cyclic number.

It is not a de Polignac number, because 1240646221 - 2⁵ = 1240646189 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1240646221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1240646521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 620323110 + 620323111.

It is an arithmetic number, because the mean of its divisors is an integer number (620323111).

Almost surely, 2^1240646221 is an apocalyptic number.

It is an amenable number.

1240646221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1240646221 is an equidigital number, since it uses as much as digits as its factorization.

1240646221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 1240646221 is about 35222.8082497691. The cubic root of 1240646221 is about 1074.5236673889.

The spelling of 1240646221 in words is "one billion, two hundred forty million, six hundred forty-six thousand, two hundred twenty-one".