1971686650 has 24 divisors (see below), whose sum is σ = 3703656924. Its totient is φ = 780864000.

The previous prime is 1971686641. The next prime is 1971686657. The reversal of 1971686650 is 566861791.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 1778393241 + 193293409 = 42171^2 + 13903^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1971686594 and 1971686603.

It is not an unprimeable number, because it can be changed into a prime (1971686657) 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 11 ways as a sum of consecutive naturals, for example, 190167 + ... + 200266.

Almost surely, 2^1971686650 is an apocalyptic number.

1971686650 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1971686650 is a deficient number, since it is larger than the sum of its proper divisors (1731970274).

1971686650 is a wasteful number, since it uses less digits than its factorization.

1971686650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390546 (or 390541 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 49.

The square root of 1971686650 is about 44403.6783386242. The cubic root of 1971686650 is about 1253.9473403488.

The spelling of 1971686650 in words is "one billion, nine hundred seventy-one million, six hundred eighty-six thousand, six hundred fifty".