16561740 has 96 divisors (see below), whose sum is σ = 52920000. Its totient is φ = 3833856.

The previous prime is 16561717. The next prime is 16561763. The reversal of 16561740 is 4716561.

It is an interprime number because it is at equal distance from previous prime (16561717) and next prime (16561763).

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

It is a junction number, because it is equal to n+sod(n) for n = 16561698 and 16561707.

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, 12636 + ... + 13884.

It is an arithmetic number, because the mean of its divisors is an integer number (551250).

Almost surely, 2^16561740 is an apocalyptic number.

16561740 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 16561740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26460000).

16561740 is an abundant number, since it is smaller than the sum of its proper divisors (36358260).

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

16561740 is a wasteful number, since it uses less digits than its factorization.

16561740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1291 (or 1289 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 16561740 is about 4069.6117750960. The cubic root of 16561740 is about 254.8993066491.

The spelling of 16561740 in words is "sixteen million, five hundred sixty-one thousand, seven hundred forty".