20778049992 has 32 divisors (see below), whose sum is σ = 59365857600. Its totient is φ = 5936585664.

The previous prime is 20778049973. The next prime is 20778049993. The reversal of 20778049992 is 29994087702.

It is a super-2 number, since 2×20778049992² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20778049993) 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, 61839267 + ... + 61839602.

It is an arithmetic number, because the mean of its divisors is an integer number (1855183050).

Almost surely, 2^20778049992 is an apocalyptic number.

It is an amenable number.

20778049992 is an abundant number, since it is smaller than the sum of its proper divisors (38587807608).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20778049992 is a wasteful number, since it uses less digits than its factorization.

20778049992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123678885 (or 123678881 counting only the distinct ones).

The product of its (nonzero) digits is 4572288, while the sum is 57.

The spelling of 20778049992 in words is "twenty billion, seven hundred seventy-eight million, forty-nine thousand, nine hundred ninety-two".