39665396121 has 64 divisors (see below), whose sum is σ = 59658633216. Its totient is φ = 23281171200.

The previous prime is 39665396107. The next prime is 39665396123. The reversal of 39665396121 is 12169356693.

It is a happy number.

It is not a de Polignac number, because 39665396121 - 2¹⁰ = 39665395097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (39665396123) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 19567510 + ... + 19569536.

It is an arithmetic number, because the mean of its divisors is an integer number (932166144).

Almost surely, 2^39665396121 is an apocalyptic number.

It is an amenable number.

39665396121 is a deficient number, since it is larger than the sum of its proper divisors (19993237095).

39665396121 is a wasteful number, since it uses less digits than its factorization.

39665396121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2342.

The product of its digits is 1574640, while the sum is 51.

The spelling of 39665396121 in words is "thirty-nine billion, six hundred sixty-five million, three hundred ninety-six thousand, one hundred twenty-one".