6821420544 has 360 divisors, whose sum is σ = 21931221312. Its totient is φ = 2031943680.

The previous prime is 6821420519. The next prime is 6821420563. The reversal of 6821420544 is 4450241286.

6821420544 is a `hidden beast` number, since 6 + 82 + 14 + 20 + 544 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 6821420499 and 6821420508.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 128706022 + ... + 128706074.

Almost surely, 2^6821420544 is an apocalyptic number.

6821420544 is a gapful number since it is divisible by the number (64) 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 6821420544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10965610656).

6821420544 is an abundant number, since it is smaller than the sum of its proper divisors (15109800768).

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

6821420544 is a wasteful number, since it uses less digits than its factorization.

6821420544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 36.

The square root of 6821420544 is about 82591.8915148455. The cubic root of 6821420544 is about 1896.5237030062.

The spelling of 6821420544 in words is "six billion, eight hundred twenty-one million, four hundred twenty thousand, five hundred forty-four".