1987664945650 has 24 divisors (see below), whose sum is σ = 3697289741124. Its totient is φ = 795015883200.

The previous prime is 1987664945639. The next prime is 1987664945677. The reversal of 1987664945650 is 565494667891.

It can be written as a sum of positive squares in 6 ways, for example, as 1398914121049 + 588750824601 = 1182757^2 + 767301^2 .

It is a hoax number, since the sum of its digits (70) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 1987664945650.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 445741 + ... + 2043040.

Almost surely, 2^{1987664945650} is an apocalyptic number.

1987664945650 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1987664945650 is a deficient number, since it is larger than the sum of its proper divisors (1709624795474).

1987664945650 is a wasteful number, since it uses less digits than its factorization.

1987664945650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2504766 (or 2504761 counting only the distinct ones).

The product of its (nonzero) digits is 391910400, while the sum is 70.

The spelling of 1987664945650 in words is "one trillion, nine hundred eighty-seven billion, six hundred sixty-four million, nine hundred forty-five thousand, six hundred fifty".