1261438487 has 2 divisors, whose sum is σ = 1261438488. Its totient is φ = 1261438486.

The previous prime is 1261438463. The next prime is 1261438523. The reversal of 1261438487 is 7848341621.

It is a weak prime.

It is an emirp because it is prime and its reverse (7848341621) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261438487 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1261437487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630719243 + 630719244.

It is an arithmetic number, because the mean of its divisors is an integer number (630719244).

Almost surely, 2^1261438487 is an apocalyptic number.

1261438487 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261438487 is an equidigital number, since it uses as much as digits as its factorization.

1261438487 is an evil number, because the sum of its binary digits is even.

The product of its digits is 258048, while the sum is 44.

The square root of 1261438487 is about 35516.7353088653. The cubic root of 1261438487 is about 1080.4931695415.

The spelling of 1261438487 in words is "one billion, two hundred sixty-one million, four hundred thirty-eight thousand, four hundred eighty-seven".