20420711280 has 80 divisors (see below), whose sum is σ = 70338012960. Its totient is φ = 5445522432.

The previous prime is 20420711237. The next prime is 20420711281. The reversal of 20420711280 is 8211702402.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×20420711280² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20420711281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4724857 + ... + 4729176.

It is an arithmetic number, because the mean of its divisors is an integer number (879225162).

Almost surely, 2^20420711280 is an apocalyptic number.

20420711280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20420711280 is an abundant number, since it is smaller than the sum of its proper divisors (49917301680).

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

20420711280 is a wasteful number, since it uses less digits than its factorization.

20420711280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9454055 (or 9454043 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The spelling of 20420711280 in words is "twenty billion, four hundred twenty million, seven hundred eleven thousand, two hundred eighty".