7720390665 has 168 divisors, whose sum is σ = 15323055552. Its totient is φ = 3730147200.

The previous prime is 7720390649. The next prime is 7720390679. The reversal of 7720390665 is 5660930277.

It is not a de Polignac number, because 7720390665 - 2⁴ = 7720390649 is a prime.

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

It is a self number, because there is not a number n which added to its sum of digits gives 7720390665.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 51128340 + ... + 51128490.

It is an arithmetic number, because the mean of its divisors is an integer number (91208664).

Almost surely, 2^7720390665 is an apocalyptic number.

It is an amenable number.

7720390665 is a deficient number, since it is larger than the sum of its proper divisors (7602664887).

7720390665 is a wasteful number, since it uses less digits than its factorization.

7720390665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283 (or 255 counting only the distinct ones).

The product of its (nonzero) digits is 476280, while the sum is 45.

The square root of 7720390665 is about 87865.7536529449. The cubic root of 7720390665 is about 1976.4223618161.

The spelling of 7720390665 in words is "seven billion, seven hundred twenty million, three hundred ninety thousand, six hundred sixty-five".