1636040644 has 12 divisors (see below), whose sum is σ = 3272081344. Its totient is φ = 701160264.

The previous prime is 1636040629. The next prime is 1636040647. The reversal of 1636040644 is 4460406361.

1636040644 is an admirable number.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (1636040647) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 29214984 + ... + 29215039.

Almost surely, 2^1636040644 is an apocalyptic number.

1636040644 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1636040644 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1636040644 is a wasteful number, since it uses less digits than its factorization.

1636040644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58430034 (or 58430032 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 34.

The square root of 1636040644 is about 40447.9992583070. Note that the first 3 decimals coincide. The cubic root of 1636040644 is about 1178.3239260884.

The spelling of 1636040644 in words is "one billion, six hundred thirty-six million, forty thousand, six hundred forty-four".