1638180072 has 64 divisors (see below), whose sum is σ = 4707432000. Its totient is φ = 527228352.

The previous prime is 1638180059. The next prime is 1638180091. The reversal of 1638180072 is 2700818361.

1638180072 is a `hidden beast` number, since 1 + 638 + 18 + 0 + 0 + 7 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

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, 124498 + ... + 137025.

It is an arithmetic number, because the mean of its divisors is an integer number (73553625).

Almost surely, 2^1638180072 is an apocalyptic number.

1638180072 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1638180072 is an abundant number, since it is smaller than the sum of its proper divisors (3069251928).

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

1638180072 is a wasteful number, since it uses less digits than its factorization.

1638180072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261567 (or 261557 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 1638180072 is about 40474.4372660078. The cubic root of 1638180072 is about 1178.8373283973.

The spelling of 1638180072 in words is "one billion, six hundred thirty-eight million, one hundred eighty thousand, seventy-two".