1661233530 has 64 divisors (see below), whose sum is σ = 4357836288. Its totient is φ = 401943360.

The previous prime is 1661233481. The next prime is 1661233547. The reversal of 1661233530 is 353321661.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 175909 + ... + 185111.

It is an arithmetic number, because the mean of its divisors is an integer number (68091192).

Almost surely, 2^1661233530 is an apocalyptic number.

1661233530 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1661233530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2178918144).

1661233530 is an abundant number, since it is smaller than the sum of its proper divisors (2696602758).

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

1661233530 is a wasteful number, since it uses less digits than its factorization.

1661233530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9771.

The product of its (nonzero) digits is 9720, while the sum is 30.

The square root of 1661233530 is about 40758.2326653156. The cubic root of 1661233530 is about 1184.3413598491.

It can be divided in two parts, 166123 and 3530, that added together give a triangular number (169653 = T₅₈₂).

The spelling of 1661233530 in words is "one billion, six hundred sixty-one million, two hundred thirty-three thousand, five hundred thirty".