1661028480 has 192 divisors, whose sum is σ = 5845034520. Its totient is φ = 434503680.

The previous prime is 1661028461. The next prime is 1661028541. The reversal of 1661028480 is 848201661.

1661028480 is a `hidden beast` number, since 16 + 610 + 28 + 4 + 8 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1573867584 + 87160896 = 39672^2 + 9336^2 .

It is a tau number, because it is divible by the number of its divisors (192).

It is a super-2 number, since 2×1661028480² = 5518031222742220800, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 302560 + ... + 308000.

Almost surely, 2^1661028480 is an apocalyptic number.

1661028480 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 1661028480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2922517260).

1661028480 is an abundant number, since it is smaller than the sum of its proper divisors (4184006040).

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

1661028480 is a wasteful number, since it uses less digits than its factorization.

1661028480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5519 (or 5504 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 1661028480 is about 40755.7171449602. The cubic root of 1661028480 is about 1184.2926291551.

The spelling of 1661028480 in words is "one billion, six hundred sixty-one million, twenty-eight thousand, four hundred eighty".