7821428340 has 384 divisors, whose sum is σ = 26475724800. Its totient is φ = 1703116800.

The previous prime is 7821428339. The next prime is 7821428341. The reversal of 7821428340 is 438241287.

It is an interprime number because it is at equal distance from previous prime (7821428339) and next prime (7821428341).

It is a super-2 number, since 2×7821428340² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7821428341) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 39303561 + ... + 39303759.

It is an arithmetic number, because the mean of its divisors is an integer number (68947200).

Almost surely, 2^7821428340 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 7821428340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13237862400).

7821428340 is an abundant number, since it is smaller than the sum of its proper divisors (18654296460).

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

7821428340 is a wasteful number, since it uses less digits than its factorization.

7821428340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383 (or 381 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 39.

The square root of 7821428340 is about 88438.8395446254. The cubic root of 7821428340 is about 1985.0069128637.

The spelling of 7821428340 in words is "seven billion, eight hundred twenty-one million, four hundred twenty-eight thousand, three hundred forty".