2191939129 has 2 divisors, whose sum is σ = 2191939130. Its totient is φ = 2191939128.

The previous prime is 2191939121. The next prime is 2191939151. The reversal of 2191939129 is 9219391912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1263091600 + 928847529 = 35540^2 + 30477^2 .

It is a cyclic number.

It is not a de Polignac number, because 2191939129 - 2³ = 2191939121 is a prime.

It is not a weakly prime, because it can be changed into another prime (2191939121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1095969564 + 1095969565.

It is an arithmetic number, because the mean of its divisors is an integer number (1095969565).

Almost surely, 2^2191939129 is an apocalyptic number.

It is an amenable number.

2191939129 is a deficient number, since it is larger than the sum of its proper divisors (1).

2191939129 is an equidigital number, since it uses as much as digits as its factorization.

2191939129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 78732, while the sum is 46.

The square root of 2191939129 is about 46818.1495683031. The cubic root of 2191939129 is about 1299.0010331462.

The spelling of 2191939129 in words is "two billion, one hundred ninety-one million, nine hundred thirty-nine thousand, one hundred twenty-nine".