665053755121 has 16 divisors (see below), whose sum is σ = 760650661888. Its totient is φ = 569604344400.

The previous prime is 665053755031. The next prime is 665053755133. The reversal of 665053755121 is 121557350566.

It is a happy number.

It is not a de Polignac number, because 665053755121 - 2²⁷ = 664919537393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665053755181) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 81189136 + ... + 81197326.

It is an arithmetic number, because the mean of its divisors is an integer number (47540666368).

Almost surely, 2^665053755121 is an apocalyptic number.

It is an amenable number.

665053755121 is a deficient number, since it is larger than the sum of its proper divisors (95596906767).

665053755121 is a wasteful number, since it uses less digits than its factorization.

665053755121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15772.

The product of its (nonzero) digits is 945000, while the sum is 46.

The spelling of 665053755121 in words is "six hundred sixty-five billion, fifty-three million, seven hundred fifty-five thousand, one hundred twenty-one".