1261531 has 2 divisors, whose sum is σ = 1261532. Its totient is φ = 1261530.

The previous prime is 1261523. The next prime is 1261549. The reversal of 1261531 is 1351621.

It is a weak prime.

It is an emirp because it is prime and its reverse (1351621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1261531 - 2³ = 1261523 is a prime.

It is a super-2 number, since 2×1261531² = 3182920927922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1261499 and 1261508.

It is not a weakly prime, because it can be changed into another prime (1261571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630765 + 630766.

It is an arithmetic number, because the mean of its divisors is an integer number (630766).

2^1261531 is an apocalyptic number.

1261531 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261531 is an equidigital number, since it uses as much as digits as its factorization.

1261531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 180, while the sum is 19.

The square root of 1261531 is about 1123.1789706009. The cubic root of 1261531 is about 108.0519583096.

The spelling of 1261531 in words is "one million, two hundred sixty-one thousand, five hundred thirty-one".