20556240136 has 8 divisors (see below), whose sum is σ = 38542950270. Its totient is φ = 10278120064.

The previous prime is 20556240119. The next prime is 20556240137. The reversal of 20556240136 is 63104265502.

It can be written as a sum of positive squares in only one way, i.e., 20479327236 + 76912900 = 143106^2 + 8770^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (20556240137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1284765001 + ... + 1284765016.

Almost surely, 2^20556240136 is an apocalyptic number.

It is an amenable number.

20556240136 is a deficient number, since it is larger than the sum of its proper divisors (17986710134).

20556240136 is a wasteful number, since it uses less digits than its factorization.

20556240136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2569530023 (or 2569530019 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 34.

The spelling of 20556240136 in words is "twenty billion, five hundred fifty-six million, two hundred forty thousand, one hundred thirty-six".