1640272138 has 8 divisors (see below), whose sum is σ = 2460600900. Its totient is φ = 820071840.

The previous prime is 1640272133. The next prime is 1640272159. The reversal of 1640272138 is 8312720461.

It can be written as a sum of positive squares in 2 ways, for example, as 1635150969 + 5121169 = 40437^2 + 2263^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (1640272133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11838 + ... + 58486.

Almost surely, 2^1640272138 is an apocalyptic number.

1640272138 is a deficient number, since it is larger than the sum of its proper divisors (820328762).

1640272138 is a wasteful number, since it uses less digits than its factorization.

1640272138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64232.

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 1640272138 is about 40500.2733077198. The cubic root of 1640272138 is about 1179.3389330833.

Adding to 1640272138 its reverse (8312720461), we get a palindrome (9952992599).

The spelling of 1640272138 in words is "one billion, six hundred forty million, two hundred seventy-two thousand, one hundred thirty-eight".