7215920640 has 800 divisors, whose sum is σ = 28876098240. Its totient is φ = 1712848896.

The previous prime is 7215920633. The next prime is 7215920707. The reversal of 7215920640 is 460295127.

7215920640 is a `hidden beast` number, since 7 + 2 + 1 + 5 + 9 + 2 + 0 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 7215920595 and 7215920604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 81077716 + ... + 81077804.

Almost surely, 2^7215920640 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 7215920640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14438049120).

7215920640 is an abundant number, since it is smaller than the sum of its proper divisors (21660177600).

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

7215920640 is a wasteful number, since it uses less digits than its factorization.

7215920640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164 (or 139 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 7215920640 is about 84946.5752105404. The cubic root of 7215920640 is about 1932.4009815453.

The spelling of 7215920640 in words is "seven billion, two hundred fifteen million, nine hundred twenty thousand, six hundred forty".