20956985280 has 1344 divisors, whose sum is σ = 98813721600. Its totient is φ = 4060938240.

The previous prime is 20956985261. The next prime is 20956985323. The reversal of 20956985280 is 8258965902.

20956985280 is a `hidden beast` number, since 20 + 9 + 5 + 6 + 98 + 528 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1344).

It is a super-2 number, since 2×20956985280² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 192265866 + ... + 192265974.

Almost surely, 2^20956985280 is an apocalyptic number.

20956985280 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 20956985280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49406860800).

20956985280 is an abundant number, since it is smaller than the sum of its proper divisors (77856736320).

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

20956985280 is a wasteful number, since it uses less digits than its factorization.

20956985280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187 (or 154 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 54.

It can be divided in two parts, 209569 and 85280, that added together give a square (294849 = 543²).

The spelling of 20956985280 in words is "twenty billion, nine hundred fifty-six million, nine hundred eighty-five thousand, two hundred eighty".