7217961660 has 864 divisors, whose sum is σ = 30435350400. Its totient is φ = 1371009024.

The previous prime is 7217961649. The next prime is 7217961679. The reversal of 7217961660 is 661697127.

It is a happy number.

7217961660 is a `hidden beast` number, since 7 + 21 + 7 + 9 + 616 + 6 + 0 = 666.

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 pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 313824409 + ... + 313824431.

It is an arithmetic number, because the mean of its divisors is an integer number (35226100).

Almost surely, 2^7217961660 is an apocalyptic number.

7217961660 is a gapful number since it is divisible by the number (70) 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 7217961660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15217675200).

7217961660 is an abundant number, since it is smaller than the sum of its proper divisors (23217388740).

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

7217961660 is a wasteful number, since it uses less digits than its factorization.

7217961660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112 (or 70 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 45.

The square root of 7217961660 is about 84958.5879119939. The cubic root of 7217961660 is about 1932.5831572947.

The spelling of 7217961660 in words is "seven billion, two hundred seventeen million, nine hundred sixty-one thousand, six hundred sixty".