786871521 has 18 divisors (see below), whose sum is σ = 1151243730. Its totient is φ = 517903776.

The previous prime is 786871499. The next prime is 786871559. The reversal of 786871521 is 125178687.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 742835025 + 44036496 = 27255^2 + 6636^2 .

It is not a de Polignac number, because 786871521 - 2¹⁴ = 786855137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (786875521) 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 17 ways as a sum of consecutive naturals, for example, 49165 + ... + 63173.

It is an arithmetic number, because the mean of its divisors is an integer number (63957985).

Almost surely, 2^786871521 is an apocalyptic number.

It is an amenable number.

786871521 is a deficient number, since it is larger than the sum of its proper divisors (364372209).

786871521 is a wasteful number, since it uses less digits than its factorization.

786871521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14173 (or 14091 counting only the distinct ones).

The product of its digits is 188160, while the sum is 45.

The square root of 786871521 is about 28051.2302938748. The cubic root of 786871521 is about 923.2116490741.

It can be divided in two parts, 78687 and 1521, that added together give a palindrome (80208).

The spelling of 786871521 in words is "seven hundred eighty-six million, eight hundred seventy-one thousand, five hundred twenty-one".