1661108400 has 360 divisors, whose sum is σ = 6818179680. Its totient is φ = 366428160.

The previous prime is 1661108389. The next prime is 1661108411. The reversal of 1661108400 is 48011661.

1661108400 is a `hidden beast` number, since 1 + 6 + 611 + 0 + 8 + 40 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (1661108389) and next prime (1661108411).

It is a tau number, because it is divible by the number of its divisors (360).

It is a super-2 number, since 2×1661108400² = 5518562233101120000, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 729664 + ... + 731936.

It is an arithmetic number, because the mean of its divisors is an integer number (18939388).

Almost surely, 2^1661108400 is an apocalyptic number.

1661108400 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 1661108400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3409089840).

1661108400 is an abundant number, since it is smaller than the sum of its proper divisors (5157071280).

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

1661108400 is a wasteful number, since it uses less digits than its factorization.

1661108400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2333 (or 2319 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 1661108400 is about 40756.6976091047. The cubic root of 1661108400 is about 1184.3116228389.

The spelling of 1661108400 in words is "one billion, six hundred sixty-one million, one hundred eight thousand, four hundred".