87235663778 has 16 divisors (see below), whose sum is σ = 138947772600. Its totient is φ = 40934443776.

The previous prime is 87235663777. The next prime is 87235663787. The reversal of 87235663778 is 87736653278.

It can be written as a sum of positive squares in 4 ways, for example, as 77878390489 + 9357273289 = 279067^2 + 96733^2 .

It is a super-2 number, since 2×87235663778² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 87235663778.

It is not an unprimeable number, because it can be changed into a prime (87235663777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3664001 + ... + 3687732.

Almost surely, 2^87235663778 is an apocalyptic number.

87235663778 is a deficient number, since it is larger than the sum of its proper divisors (51712108822).

87235663778 is a wasteful number, since it uses less digits than its factorization.

87235663778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7352101.

The product of its digits is 71124480, while the sum is 62.

The spelling of 87235663778 in words is "eighty-seven billion, two hundred thirty-five million, six hundred sixty-three thousand, seven hundred seventy-eight".