1261670537 has 2 divisors, whose sum is σ = 1261670538. Its totient is φ = 1261670536.

The previous prime is 1261670513. The next prime is 1261670539. The reversal of 1261670537 is 7350761621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1260889081 + 781456 = 35509^2 + 884^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261670537 is a prime.

Together with 1261670539, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1261670537.

It is not a weakly prime, because it can be changed into another prime (1261670539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630835268 + 630835269.

It is an arithmetic number, because the mean of its divisors is an integer number (630835269).

Almost surely, 2^1261670537 is an apocalyptic number.

It is an amenable number.

1261670537 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261670537 is an equidigital number, since it uses as much as digits as its factorization.

1261670537 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52920, while the sum is 38.

The square root of 1261670537 is about 35520.0019284909. The cubic root of 1261670537 is about 1080.5594201143.

The spelling of 1261670537 in words is "one billion, two hundred sixty-one million, six hundred seventy thousand, five hundred thirty-seven".