20678636255990 has 32 divisors (see below), whose sum is σ = 38019207375360. Its totient is φ = 8094249165664.

The previous prime is 20678636255987. The next prime is 20678636256127. The reversal of 20678636255990 is 9955263687602.

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 20678636255990.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 173852 + ... + 6433311.

It is an arithmetic number, because the mean of its divisors is an integer number (1188100230480).

Almost surely, 2^{20678636255990} is an apocalyptic number.

20678636255990 is a deficient number, since it is larger than the sum of its proper divisors (17340571119370).

20678636255990 is a wasteful number, since it uses less digits than its factorization.

20678636255990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6613876.

The product of its (nonzero) digits is 293932800, while the sum is 68.

The spelling of 20678636255990 in words is "twenty trillion, six hundred seventy-eight billion, six hundred thirty-six million, two hundred fifty-five thousand, nine hundred ninety".