1138947961 has 2 divisors, whose sum is σ = 1138947962. Its totient is φ = 1138947960.

The previous prime is 1138947937. The next prime is 1138947973. The reversal of 1138947961 is 1697498311.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1089330025 + 49617936 = 33005^2 + 7044^2 .

It is a cyclic number.

It is not a de Polignac number, because 1138947961 - 2¹⁹ = 1138423673 is a prime.

It is not a weakly prime, because it can be changed into another prime (1138941961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 569473980 + 569473981.

It is an arithmetic number, because the mean of its divisors is an integer number (569473981).

Almost surely, 2^1138947961 is an apocalyptic number.

It is an amenable number.

1138947961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1138947961 is an equidigital number, since it uses as much as digits as its factorization.

1138947961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 49.

The square root of 1138947961 is about 33748.3030832663. The cubic root of 1138947961 is about 1044.3224810928.

The spelling of 1138947961 in words is "one billion, one hundred thirty-eight million, nine hundred forty-seven thousand, nine hundred sixty-one".