20178934669 has 16 divisors (see below), whose sum is σ = 21576432240. Its totient is φ = 18805063680.

The previous prime is 20178934621. The next prime is 20178934673. The reversal of 20178934669 is 96643987102.

It can be written as a sum of positive squares in 8 ways, for example, as 4362602500 + 15816332169 = 66050^2 + 125763^2 .

It is not a de Polignac number, because 20178934669 - 2¹⁷ = 20178803597 is a prime.

It is a super-2 number, since 2×20178934669² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20178934969) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3853477 + ... + 3858709.

It is an arithmetic number, because the mean of its divisors is an integer number (1348527015).

Almost surely, 2^20178934669 is an apocalyptic number.

It is an amenable number.

20178934669 is a deficient number, since it is larger than the sum of its proper divisors (1397497571).

20178934669 is a wasteful number, since it uses less digits than its factorization.

20178934669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7440.

The product of its (nonzero) digits is 3919104, while the sum is 55.

The spelling of 20178934669 in words is "twenty billion, one hundred seventy-eight million, nine hundred thirty-four thousand, six hundred sixty-nine".