21420780480 has 672 divisors, whose sum is σ = 84674903040. Its totient is φ = 5111009280.

The previous prime is 21420780431. The next prime is 21420780497. The reversal of 21420780480 is 8408702412.

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

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, 67573282 + ... + 67573598.

It is an arithmetic number, because the mean of its divisors is an integer number (126004320).

Almost surely, 2^21420780480 is an apocalyptic number.

21420780480 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 21420780480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42337451520).

21420780480 is an abundant number, since it is smaller than the sum of its proper divisors (63254122560).

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

21420780480 is a wasteful number, since it uses less digits than its factorization.

21420780480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439 (or 417 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 36.

The spelling of 21420780480 in words is "twenty-one billion, four hundred twenty million, seven hundred eighty thousand, four hundred eighty".