1661604054 has 64 divisors (see below), whose sum is σ = 3704279040. Its totient is φ = 492660000.

The previous prime is 1661604053. The next prime is 1661604059. The reversal of 1661604054 is 4504061661.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661604053) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 650079 + ... + 652629.

It is an arithmetic number, because the mean of its divisors is an integer number (57879360).

Almost surely, 2^1661604054 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1661604054, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1852139520).

1661604054 is an abundant number, since it is smaller than the sum of its proper divisors (2042674986).

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

1661604054 is a wasteful number, since it uses less digits than its factorization.

1661604054 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2777.

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 1661604054 is about 40762.7778003413. Note that the first 3 decimals coincide. The cubic root of 1661604054 is about 1184.4294057236.

The spelling of 1661604054 in words is "one billion, six hundred sixty-one million, six hundred four thousand, fifty-four".