1661319072 has 288 divisors, whose sum is σ = 5847109632. Its totient is φ = 453682944.

The previous prime is 1661319029. The next prime is 1661319113. The reversal of 1661319072 is 2709131661.

It is a tau number, because it is divible by the number of its divisors (288).

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 47 ways as a sum of consecutive naturals, for example, 1251273 + ... + 1252599.

It is an arithmetic number, because the mean of its divisors is an integer number (20302464).

Almost surely, 2^1661319072 is an apocalyptic number.

1661319072 is a gapful number since it is divisible by the number (12) 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 1661319072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2923554816).

1661319072 is an abundant number, since it is smaller than the sum of its proper divisors (4185790560).

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

1661319072 is a wasteful number, since it uses less digits than its factorization.

1661319072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1382 (or 1362 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 1661319072 is about 40759.2820348936. The cubic root of 1661319072 is about 1184.3616879543.

The spelling of 1661319072 in words is "one billion, six hundred sixty-one million, three hundred nineteen thousand, seventy-two".