821381292426240 has 2112 divisors, whose sum is σ = 3635812211006976. Its totient is φ = 173148469198848.

The previous prime is 821381292426181. The next prime is 821381292426283. The reversal of 821381292426240 is 42624292183128.

821381292426240 is a `hidden beast` number, since 8 + 2 + 1 + 3 + 8 + 1 + 2 + 9 + 2 + 4 + 2 + 624 + 0 = 666.

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

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, 164506565184 + ... + 164506570176.

It is an arithmetic number, because the mean of its divisors is an integer number (1721501993848).

Almost surely, 2^{821381292426240} is an apocalyptic number.

821381292426240 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 821381292426240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1817906105503488).

821381292426240 is an abundant number, since it is smaller than the sum of its proper divisors (2814430918580736).

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

821381292426240 is a wasteful number, since it uses less digits than its factorization.

821381292426240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6506 (or 6476 counting only the distinct ones).

The product of its (nonzero) digits is 5308416, while the sum is 54.

The spelling of 821381292426240 in words is "eight hundred twenty-one trillion, three hundred eighty-one billion, two hundred ninety-two million, four hundred twenty-six thousand, two hundred forty".