20836506778 has 4 divisors (see below), whose sum is σ = 31254760170. Its totient is φ = 10418253388.

The previous prime is 20836506767. The next prime is 20836506781. The reversal of 20836506778 is 87760563802.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 10735653769 + 10100853009 = 103613^2 + 100503^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5209126693 + ... + 5209126696.

Almost surely, 2^20836506778 is an apocalyptic number.

20836506778 is a deficient number, since it is larger than the sum of its proper divisors (10418253392).

20836506778 is a wasteful number, since it uses less digits than its factorization.

20836506778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10418253391.

The product of its (nonzero) digits is 3386880, while the sum is 52.

The spelling of 20836506778 in words is "twenty billion, eight hundred thirty-six million, five hundred six thousand, seven hundred seventy-eight".