621532783872 has 1728 divisors, whose sum is σ = 2581332606720. Its totient is φ = 144919756800.

The previous prime is 621532783853. The next prime is 621532783889. The reversal of 621532783872 is 278387235126.

621532783872 is a `hidden beast` number, since 6 + 2 + 1 + 532 + 7 + 8 + 38 + 72 = 666.

It is a tau number, because it is divible by the number of its divisors (1728).

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, 1985727588 + ... + 1985727900.

It is an arithmetic number, because the mean of its divisors is an integer number (1493826740).

Almost surely, 2^621532783872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 621532783872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1290666303360).

621532783872 is an abundant number, since it is smaller than the sum of its proper divisors (1959799822848).

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

621532783872 is a wasteful number, since it uses less digits than its factorization.

621532783872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417 (or 390 counting only the distinct ones).

The product of its digits is 6773760, while the sum is 54.

The spelling of 621532783872 in words is "six hundred twenty-one billion, five hundred thirty-two million, seven hundred eighty-three thousand, eight hundred seventy-two".