1287647401 has 2 divisors, whose sum is σ = 1287647402. Its totient is φ = 1287647400.

The previous prime is 1287647399. The next prime is 1287647429. The reversal of 1287647401 is 1047467821.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1281640000 + 6007401 = 35800^2 + 2451^2 .

It is an emirp because it is prime and its reverse (1047467821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1287647401 - 2¹ = 1287647399 is a prime.

Together with 1287647399, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1287641401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 643823700 + 643823701.

It is an arithmetic number, because the mean of its divisors is an integer number (643823701).

Almost surely, 2^1287647401 is an apocalyptic number.

It is an amenable number.

1287647401 is a deficient number, since it is larger than the sum of its proper divisors (1).

1287647401 is an equidigital number, since it uses as much as digits as its factorization.

1287647401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75264, while the sum is 40.

The square root of 1287647401 is about 35883.8041600943. The cubic root of 1287647401 is about 1087.9250712641.

The spelling of 1287647401 in words is "one billion, two hundred eighty-seven million, six hundred forty-seven thousand, four hundred one".