1638960780 has 48 divisors (see below), whose sum is σ = 4590964224. Its totient is φ = 436877760.

The previous prime is 1638960761. The next prime is 1638960787. The reversal of 1638960780 is 870698361.

It is not an unprimeable number, because it can be changed into a prime (1638960787) 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 15 ways as a sum of consecutive naturals, for example, 214099 + ... + 221621.

It is an arithmetic number, because the mean of its divisors is an integer number (95645088).

Almost surely, 2^1638960780 is an apocalyptic number.

1638960780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1638960780 is an abundant number, since it is smaller than the sum of its proper divisors (2952003444).

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

1638960780 is a wasteful number, since it uses less digits than its factorization.

1638960780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11166 (or 11164 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 48.

The square root of 1638960780 is about 40484.0805749618. The cubic root of 1638960780 is about 1179.0245649506.

The spelling of 1638960780 in words is "one billion, six hundred thirty-eight million, nine hundred sixty thousand, seven hundred eighty".