3261689856 has 312 divisors, whose sum is σ = 10196812080. Its totient is φ = 1040449536.

The previous prime is 3261689839. The next prime is 3261689857. The reversal of 3261689856 is 6589861623.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3261689857) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28864456 + ... + 28864568.

It is an arithmetic number, because the mean of its divisors is an integer number (32682090).

Almost surely, 2^3261689856 is an apocalyptic number.

3261689856 is a gapful number since it is divisible by the number (36) 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 3261689856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5098406040).

3261689856 is an abundant number, since it is smaller than the sum of its proper divisors (6935122224).

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

3261689856 is an equidigital number, since it uses as much as digits as its factorization.

3261689856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181 (or 147 counting only the distinct ones).

The product of its digits is 3732480, while the sum is 54.

The square root of 3261689856 is about 57111.2060457490. The cubic root of 3261689856 is about 1483.0218656837.

The spelling of 3261689856 in words is "three billion, two hundred sixty-one million, six hundred eighty-nine thousand, eight hundred fifty-six".