1640165121 has 48 divisors (see below), whose sum is σ = 2832710400. Its totient is φ = 894136320.

The previous prime is 1640165041. The next prime is 1640165123. The reversal of 1640165121 is 1215610461.

1640165121 is a `hidden beast` number, since 1 + 6 + 4 + 0 + 1 + 651 + 2 + 1 = 666.

It is not a de Polignac number, because 1640165121 - 2⁷ = 1640164993 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1640165123) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 649341 + ... + 651861.

It is an arithmetic number, because the mean of its divisors is an integer number (59014800).

Almost surely, 2^1640165121 is an apocalyptic number.

It is an amenable number.

1640165121 is a deficient number, since it is larger than the sum of its proper divisors (1192545279).

1640165121 is a wasteful number, since it uses less digits than its factorization.

1640165121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3006 (or 3003 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 1640165121 is about 40498.9520975543. The cubic root of 1640165121 is about 1179.3132844817.

Adding to 1640165121 its reverse (1215610461), we get a palindrome (2855775582).

The spelling of 1640165121 in words is "one billion, six hundred forty million, one hundred sixty-five thousand, one hundred twenty-one".