1971889851 has 8 divisors (see below), whose sum is σ = 2631095824. Its totient is φ = 1313638560.

The previous prime is 1971889807. The next prime is 1971889853. The reversal of 1971889851 is 1589881791.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1971889851 - 2¹¹ = 1971887803 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1971889791 and 1971889800.

It is not an unprimeable number, because it can be changed into a prime (1971889853) 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 7 ways as a sum of consecutive naturals, for example, 233836 + ... + 242121.

It is an arithmetic number, because the mean of its divisors is an integer number (328886978).

Almost surely, 2^1971889851 is an apocalyptic number.

1971889851 is a deficient number, since it is larger than the sum of its proper divisors (659205973).

1971889851 is a wasteful number, since it uses less digits than its factorization.

1971889851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477341.

The product of its digits is 1451520, while the sum is 57.

The square root of 1971889851 is about 44405.9663896644. The cubic root of 1971889851 is about 1253.9904159225.

The spelling of 1971889851 in words is "one billion, nine hundred seventy-one million, eight hundred eighty-nine thousand, eight hundred fifty-one".