1681499520 has 512 divisors, whose sum is σ = 6376550400. Its totient is φ = 418037760.

The previous prime is 1681499513. The next prime is 1681499531. The reversal of 1681499520 is 259941861.

1681499520 is a `hidden beast` number, since 1 + 6 + 81 + 49 + 9 + 520 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 23034204 + ... + 23034276.

It is an arithmetic number, because the mean of its divisors is an integer number (12454200).

Almost surely, 2^1681499520 is an apocalyptic number.

1681499520 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 1681499520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3188275200).

1681499520 is an abundant number, since it is smaller than the sum of its proper divisors (4695050880).

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

1681499520 is a wasteful number, since it uses less digits than its factorization.

1681499520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175 (or 157 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The square root of 1681499520 is about 41006.0912548368. The cubic root of 1681499520 is about 1189.1379770337.

The spelling of 1681499520 in words is "one billion, six hundred eighty-one million, four hundred ninety-nine thousand, five hundred twenty".