1971129449 has 4 divisors (see below), whose sum is σ = 2039099460. Its totient is φ = 1903159440.

The previous prime is 1971129409. The next prime is 1971129467. The reversal of 1971129449 is 9449211791.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 978438400 + 992691049 = 31280^2 + 31507^2 .

It is a cyclic number.

It is not a de Polignac number, because 1971129449 - 2¹² = 1971125353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1971129409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33984962 + ... + 33985019.

It is an arithmetic number, because the mean of its divisors is an integer number (509774865).

Almost surely, 2^1971129449 is an apocalyptic number.

It is an amenable number.

1971129449 is a deficient number, since it is larger than the sum of its proper divisors (67970011).

1971129449 is an equidigital number, since it uses as much as digits as its factorization.

1971129449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67970010.

The product of its digits is 163296, while the sum is 47.

The square root of 1971129449 is about 44397.4036290412. The cubic root of 1971129449 is about 1253.8292068817.

The spelling of 1971129449 in words is "one billion, nine hundred seventy-one million, one hundred twenty-nine thousand, four hundred forty-nine".