1999956149 has 2 divisors, whose sum is σ = 1999956150. Its totient is φ = 1999956148.

The previous prime is 1999956083. The next prime is 1999956163. The reversal of 1999956149 is 9416599991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1443468049 + 556488100 = 37993^2 + 23590^2 .

It is an emirp because it is prime and its reverse (9416599991) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1999956149 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1999956091 and 1999956100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1999956349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999978074 + 999978075.

It is an arithmetic number, because the mean of its divisors is an integer number (999978075).

Almost surely, 2^1999956149 is an apocalyptic number.

It is an amenable number.

1999956149 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999956149 is an equidigital number, since it uses as much as digits as its factorization.

1999956149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7085880, while the sum is 62.

The square root of 1999956149 is about 44720.8692782240. The cubic root of 1999956149 is about 1259.9118416946.

The spelling of 1999956149 in words is "one billion, nine hundred ninety-nine million, nine hundred fifty-six thousand, one hundred forty-nine".