1605213612 has 60 divisors (see below), whose sum is σ = 4243571640. Its totient is φ = 529049664.

The previous prime is 1605213611. The next prime is 1605213691. The reversal of 1605213612 is 2163125061.

1605213612 is a `hidden beast` number, since 1 + 605 + 21 + 36 + 1 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1605213611) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1003 + ... + 56669.

It is an arithmetic number, because the mean of its divisors is an integer number (70726194).

Almost surely, 2^1605213612 is an apocalyptic number.

1605213612 is a gapful number since it is divisible by the number (12) 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 1605213612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2121785820).

1605213612 is an abundant number, since it is smaller than the sum of its proper divisors (2638358028).

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

1605213612 is a wasteful number, since it uses less digits than its factorization.

1605213612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55772 (or 55761 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 1605213612 is about 40065.1171469646. The cubic root of 1605213612 is about 1170.8761090820.

Adding to 1605213612 its reverse (2163125061), we get a palindrome (3768338673).

The spelling of 1605213612 in words is "one billion, six hundred five million, two hundred thirteen thousand, six hundred twelve".