20778066400 has 576 divisors, whose sum is σ = 67153701888. Its totient is φ = 6091407360.

The previous prime is 20778066373. The next prime is 20778066497. The reversal of 20778066400 is 466087702.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 127472719 + ... + 127472881.

It is an arithmetic number, because the mean of its divisors is an integer number (116586288).

Almost surely, 2^20778066400 is an apocalyptic number.

20778066400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20778066400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33576850944).

20778066400 is an abundant number, since it is smaller than the sum of its proper divisors (46375635488).

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

20778066400 is a wasteful number, since it uses less digits than its factorization.

20778066400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323 (or 310 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 40.

The spelling of 20778066400 in words is "twenty billion, seven hundred seventy-eight million, sixty-six thousand, four hundred".