1280631397 has 2 divisors, whose sum is σ = 1280631398. Its totient is φ = 1280631396.

The previous prime is 1280631389. The next prime is 1280631409. The reversal of 1280631397 is 7931360821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 899640036 + 380991361 = 29994^2 + 19519^2 .

It is an emirp because it is prime and its reverse (7931360821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1280631397 - 2³ = 1280631389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1280631197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640315698 + 640315699.

It is an arithmetic number, because the mean of its divisors is an integer number (640315699).

Almost surely, 2^1280631397 is an apocalyptic number.

It is an amenable number.

1280631397 is a deficient number, since it is larger than the sum of its proper divisors (1).

1280631397 is an equidigital number, since it uses as much as digits as its factorization.

1280631397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 1280631397 is about 35785.9105934165. The cubic root of 1280631397 is about 1085.9455459516.

The spelling of 1280631397 in words is "one billion, two hundred eighty million, six hundred thirty-one thousand, three hundred ninety-seven".