1261377973 has 2 divisors, whose sum is σ = 1261377974. Its totient is φ = 1261377972.

The previous prime is 1261377913. The next prime is 1261378007. The reversal of 1261377973 is 3797731621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1260037009 + 1340964 = 35497^2 + 1158^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261377973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1261377913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630688986 + 630688987.

It is an arithmetic number, because the mean of its divisors is an integer number (630688987).

Almost surely, 2^1261377973 is an apocalyptic number.

It is an amenable number.

1261377973 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261377973 is an equidigital number, since it uses as much as digits as its factorization.

1261377973 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 333396, while the sum is 46.

The square root of 1261377973 is about 35515.8833903931. The cubic root of 1261377973 is about 1080.4758913812.

The spelling of 1261377973 in words is "one billion, two hundred sixty-one million, three hundred seventy-seven thousand, nine hundred seventy-three".