1661837520 has 160 divisors (see below), whose sum is σ = 5919621120. Its totient is φ = 377786880.

The previous prime is 1661837497. The next prime is 1661837539. The reversal of 1661837520 is 257381661.

It is a congruent number.

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, 318291 + ... + 323469.

It is an arithmetic number, because the mean of its divisors is an integer number (36997632).

Almost surely, 2^1661837520 is an apocalyptic number.

1661837520 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 1661837520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2959810560).

1661837520 is an abundant number, since it is smaller than the sum of its proper divisors (4257783600).

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

1661837520 is a wasteful number, since it uses less digits than its factorization.

1661837520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5393 (or 5387 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 39.

The square root of 1661837520 is about 40765.6414152899. The cubic root of 1661837520 is about 1184.4848764287.

The spelling of 1661837520 in words is "one billion, six hundred sixty-one million, eight hundred thirty-seven thousand, five hundred twenty".