1638466560 has 396 divisors, whose sum is σ = 6024836844. Its totient is φ = 411402240.

The previous prime is 1638466549. The next prime is 1638466561. The reversal of 1638466560 is 656648361.

1638466560 is a `hidden beast` number, since 1 + 6 + 3 + 84 + 6 + 6 + 560 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1071645696 + 566820864 = 32736^2 + 23808^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1638466561) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 44282862 + ... + 44282898.

Almost surely, 2^1638466560 is an apocalyptic number.

1638466560 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1638466560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3012418422).

1638466560 is an abundant number, since it is smaller than the sum of its proper divisors (4386370284).

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

1638466560 is a wasteful number, since it uses less digits than its factorization.

1638466560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The square root of 1638466560 is about 40477.9762339967. The cubic root of 1638466560 is about 1178.9060434852.

It can be divided in two parts, 16384 and 66560, that added together give a square (82944 = 288²).

The spelling of 1638466560 in words is "one billion, six hundred thirty-eight million, four hundred sixty-six thousand, five hundred sixty".