1263391 has 2 divisors, whose sum is σ = 1263392. Its totient is φ = 1263390.

The previous prime is 1263377. The next prime is 1263403. The reversal of 1263391 is 1933621.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1263391 - 2⁷ = 1263263 is a prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1263331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 631695 + 631696.

It is an arithmetic number, because the mean of its divisors is an integer number (631696).

2^1263391 is an apocalyptic number.

1263391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1263391 is an equidigital number, since it uses as much as digits as its factorization.

1263391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 972, while the sum is 25.

The square root of 1263391 is about 1124.0066725781. The cubic root of 1263391 is about 108.1050361306.

The spelling of 1263391 in words is "one million, two hundred sixty-three thousand, three hundred ninety-one".