1640409215 has 16 divisors (see below), whose sum is σ = 2042107200. Its totient is φ = 1263505152.

The previous prime is 1640409119. The next prime is 1640409223. The reversal of 1640409215 is 5129040461.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1640409215 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36299 + ... + 67811.

It is an arithmetic number, because the mean of its divisors is an integer number (127631700).

Almost surely, 2^1640409215 is an apocalyptic number.

1640409215 is a deficient number, since it is larger than the sum of its proper divisors (401697985).

1640409215 is a wasteful number, since it uses less digits than its factorization.

1640409215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31906.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 1640409215 is about 40501.9655695869. The cubic root of 1640409215 is about 1179.3717844897.

Adding to 1640409215 its reverse (5129040461), we get a palindrome (6769449676).

The spelling of 1640409215 in words is "one billion, six hundred forty million, four hundred nine thousand, two hundred fifteen".