1961871137 has 2 divisors, whose sum is σ = 1961871138. Its totient is φ = 1961871136.

The previous prime is 1961871103. The next prime is 1961871193. The reversal of 1961871137 is 7311781691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1818254881 + 143616256 = 42641^2 + 11984^2 .

It is an emirp because it is prime and its reverse (7311781691) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1961871137 - 2⁶ = 1961871073 is a prime.

It is not a weakly prime, because it can be changed into another prime (1961871937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 980935568 + 980935569.

It is an arithmetic number, because the mean of its divisors is an integer number (980935569).

Almost surely, 2^1961871137 is an apocalyptic number.

It is an amenable number.

1961871137 is a deficient number, since it is larger than the sum of its proper divisors (1).

1961871137 is an equidigital number, since it uses as much as digits as its factorization.

1961871137 is an evil number, because the sum of its binary digits is even.

The product of its digits is 63504, while the sum is 44.

The square root of 1961871137 is about 44293.0145395411. The cubic root of 1961871137 is about 1251.8630643733.

The spelling of 1961871137 in words is "one billion, nine hundred sixty-one million, eight hundred seventy-one thousand, one hundred thirty-seven".