1601220736 has 64 divisors (see below), whose sum is σ = 3267290520. Its totient is φ = 781361152.

The previous prime is 1601220707. The next prime is 1601220737. The reversal of 1601220736 is 6370221061.

It can be written as a sum of positive squares in 4 ways, for example, as 764854336 + 836366400 = 27656^2 + 28920^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (1601220737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1580166 + ... + 1581178.

Almost surely, 2^1601220736 is an apocalyptic number.

1601220736 is a gapful number since it is divisible by the number (16) 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 1601220736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1633645260).

1601220736 is an abundant number, since it is smaller than the sum of its proper divisors (1666069784).

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

1601220736 is a wasteful number, since it uses less digits than its factorization.

1601220736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1313 (or 1301 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 1601220736 is about 40015.2562905700. The cubic root of 1601220736 is about 1169.9044741450.

Adding to 1601220736 its reverse (6370221061), we get a palindrome (7971441797).

The spelling of 1601220736 in words is "one billion, six hundred one million, two hundred twenty thousand, seven hundred thirty-six".