1640631012 has 12 divisors (see below), whose sum is σ = 3828139056. Its totient is φ = 546877000.

The previous prime is 1640631001. The next prime is 1640631017. The reversal of 1640631012 is 2101360461.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×1640631012² = 5383340235072288288, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1640631017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68359614 + ... + 68359637.

It is an arithmetic number, because the mean of its divisors is an integer number (319011588).

Almost surely, 2^1640631012 is an apocalyptic number.

1640631012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1640631012 is an abundant number, since it is smaller than the sum of its proper divisors (2187508044).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1640631012 is a wasteful number, since it uses less digits than its factorization.

1640631012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136719258 (or 136719256 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 1640631012 is about 40504.7035787203. The cubic root of 1640631012 is about 1179.4249357263.

Adding to 1640631012 its reverse (2101360461), we get a palindrome (3741991473).

The spelling of 1640631012 in words is "one billion, six hundred forty million, six hundred thirty-one thousand, twelve".