1994137261 has 2 divisors, whose sum is σ = 1994137262. Its totient is φ = 1994137260.

The previous prime is 1994137241. The next prime is 1994137309. The reversal of 1994137261 is 1627314991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1647954025 + 346183236 = 40595^2 + 18606^2 .

It is a cyclic number.

It is not a de Polignac number, because 1994137261 - 2⁷ = 1994137133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1994137231) 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, 997068630 + 997068631.

It is an arithmetic number, because the mean of its divisors is an integer number (997068631).

Almost surely, 2^1994137261 is an apocalyptic number.

It is an amenable number.

1994137261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1994137261 is an equidigital number, since it uses as much as digits as its factorization.

1994137261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 43.

The square root of 1994137261 is about 44655.7640288463. The cubic root of 1994137261 is about 1258.6887469516.

The spelling of 1994137261 in words is "one billion, nine hundred ninety-four million, one hundred thirty-seven thousand, two hundred sixty-one".