7865406720 has 288 divisors, whose sum is σ = 28670288640. Its totient is φ = 2040422400.

The previous prime is 7865406719. The next prime is 7865406733. The reversal of 7865406720 is 276045687.

7865406720 is a `hidden beast` number, since 7 + 86 + 540 + 6 + 7 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-3 number, since 3×7865406720³ (a number of 31 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1275645 + ... + 1281795.

Almost surely, 2^7865406720 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 7865406720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14335144320).

7865406720 is an abundant number, since it is smaller than the sum of its proper divisors (20804881920).

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

7865406720 is a wasteful number, since it uses less digits than its factorization.

7865406720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6218 (or 6198 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 45.

The square root of 7865406720 is about 88687.1282656057. The cubic root of 7865406720 is about 1988.7203982166.

The spelling of 7865406720 in words is "seven billion, eight hundred sixty-five million, four hundred six thousand, seven hundred twenty".