20278637720 has 128 divisors (see below), whose sum is σ = 51362035200. Its totient is φ = 7141555200.

The previous prime is 20278637713. The next prime is 20278637789. The reversal of 20278637720 is 2773687202.

It is a super-2 number, since 2×20278637720² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2503517 + ... + 2511603.

It is an arithmetic number, because the mean of its divisors is an integer number (401265900).

Almost surely, 2^20278637720 is an apocalyptic number.

20278637720 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 20278637720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25681017600).

20278637720 is an abundant number, since it is smaller than the sum of its proper divisors (31083397480).

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

20278637720 is a wasteful number, since it uses less digits than its factorization.

20278637720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8289 (or 8285 counting only the distinct ones).

The product of its (nonzero) digits is 395136, while the sum is 44.

The spelling of 20278637720 in words is "twenty billion, two hundred seventy-eight million, six hundred thirty-seven thousand, seven hundred twenty".