7917639840 has 768 divisors, whose sum is σ = 32672263680. Its totient is φ = 1806520320.

The previous prime is 7917639811. The next prime is 7917639883. The reversal of 7917639840 is 489367197.

It is a happy number.

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 127 ways as a sum of consecutive naturals, for example, 465743512 + ... + 465743528.

It is an arithmetic number, because the mean of its divisors is an integer number (42542010).

Almost surely, 2^7917639840 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 7917639840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16336131840).

7917639840 is an abundant number, since it is smaller than the sum of its proper divisors (24754623840).

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

7917639840 is an equidigital number, since it uses as much as digits as its factorization.

7917639840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86 (or 38 counting only the distinct ones).

The product of its (nonzero) digits is 2286144, while the sum is 54.

The square root of 7917639840 is about 88981.1206942237. The cubic root of 7917639840 is about 1993.1129649290.

The spelling of 7917639840 in words is "seven billion, nine hundred seventeen million, six hundred thirty-nine thousand, eight hundred forty".