821461254228720 has 320 divisors, whose sum is σ = 3234183055703040. Its totient is φ = 187733870595072.

The previous prime is 821461254228707. The next prime is 821461254228743. The reversal of 821461254228720 is 27822452164128.

821461254228720 is a `hidden beast` number, since 8 + 2 + 1 + 4 + 6 + 1 + 2 + 542 + 28 + 72 + 0 = 666.

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 63 ways as a sum of consecutive naturals, for example, 94841454 + ... + 103139826.

It is an arithmetic number, because the mean of its divisors is an integer number (10106822049072).

Almost surely, 2^{821461254228720} is an apocalyptic number.

821461254228720 is a gapful number since it is divisible by the number (80) 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 821461254228720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1617091527851520).

821461254228720 is an abundant number, since it is smaller than the sum of its proper divisors (2412721801474320).

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

821461254228720 is a wasteful number, since it uses less digits than its factorization.

821461254228720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8304949 (or 8304937 counting only the distinct ones).

The product of its (nonzero) digits is 6881280, while the sum is 54.

The spelling of 821461254228720 in words is "eight hundred twenty-one trillion, four hundred sixty-one billion, two hundred fifty-four million, two hundred twenty-eight thousand, seven hundred twenty".