1247840641 has 2 divisors, whose sum is σ = 1247840642. Its totient is φ = 1247840640.

The previous prime is 1247840603. The next prime is 1247840653. The reversal of 1247840641 is 1460487421.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 712890000 + 534950641 = 26700^2 + 23129^2 .

It is a cyclic number.

It is not a de Polignac number, because 1247840641 - 2¹⁷ = 1247709569 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1247840641.

It is not a weakly prime, because it can be changed into another prime (1247840141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 623920320 + 623920321.

It is an arithmetic number, because the mean of its divisors is an integer number (623920321).

Almost surely, 2^1247840641 is an apocalyptic number.

It is an amenable number.

1247840641 is a deficient number, since it is larger than the sum of its proper divisors (1).

1247840641 is an equidigital number, since it uses as much as digits as its factorization.

1247840641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43008, while the sum is 37.

The square root of 1247840641 is about 35324.7879116068. The cubic root of 1247840641 is about 1076.5966944316.

The spelling of 1247840641 in words is "one billion, two hundred forty-seven million, eight hundred forty thousand, six hundred forty-one".