1661914800 has 960 divisors, whose sum is σ = 7749504000. Its totient is φ = 328458240.

The previous prime is 1661914789. The next prime is 1661914801. The reversal of 1661914800 is 84191661.

It is a happy number.

1661914800 is a `hidden beast` number, since 166 + 19 + 1 + 480 + 0 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (1661914801) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 18673156 + ... + 18673244.

It is an arithmetic number, because the mean of its divisors is an integer number (8072400).

Almost surely, 2^1661914800 is an apocalyptic number.

1661914800 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 1661914800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3874752000).

1661914800 is an abundant number, since it is smaller than the sum of its proper divisors (6087589200).

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

1661914800 is a wasteful number, since it uses less digits than its factorization.

1661914800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155 (or 138 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 1661914800 is about 40766.5892613056. The cubic root of 1661914800 is about 1184.5032367420.

The spelling of 1661914800 in words is "one billion, six hundred sixty-one million, nine hundred fourteen thousand, eight hundred".