1661451444 has 18 divisors (see below), whose sum is σ = 4199780130. Its totient is φ = 553817136.

The previous prime is 1661451439. The next prime is 1661451511. The reversal of 1661451444 is 4441541661.

1661451444 is a `hidden beast` number, since 166 + 1 + 4 + 51 + 444 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1615075344 + 46376100 = 40188^2 + 6810^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-6 number, since 6×1661451444⁶ (a number of 57 digits) contains 666666 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 46151429 = 1661451444 / (1 + 6 + 6 + 1 + 4 + 5 + 1 + 4 + 4 + 4).

It is a junction number, because it is equal to n+sod(n) for n = 1661451399 and 1661451408.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 23075679 + ... + 23075750.

Almost surely, 2^1661451444 is an apocalyptic number.

It is an amenable number.

1661451444 is an abundant number, since it is smaller than the sum of its proper divisors (2538328686).

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

1661451444 is a wasteful number, since it uses less digits than its factorization.

1661451444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46151439 (or 46151434 counting only the distinct ones).

The product of its digits is 46080, while the sum is 36.

The square root of 1661451444 is about 40760.9058289926. The cubic root of 1661451444 is about 1184.3931433129.

The spelling of 1661451444 in words is "one billion, six hundred sixty-one million, four hundred fifty-one thousand, four hundred forty-four".