1313221644 has 72 divisors (see below), whose sum is σ = 4016926368. Its totient is φ = 353134080.

The previous prime is 1313221631. The next prime is 1313221687. The reversal of 1313221644 is 4461223131.

It is a happy number.

1313221644 is a `hidden beast` number, since 1 + 3 + 13 + 2 + 2 + 1 + 644 = 666.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 148987 + ... + 157554.

It is an arithmetic number, because the mean of its divisors is an integer number (55790644).

Almost surely, 2^1313221644 is an apocalyptic number.

1313221644 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1313221644 is an abundant number, since it is smaller than the sum of its proper divisors (2703704724).

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

1313221644 is a wasteful number, since it uses less digits than its factorization.

1313221644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306575 (or 306570 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 1313221644 is about 36238.4001302486. The cubic root of 1313221644 is about 1095.0804119343.

Adding to 1313221644 its reverse (4461223131), we get a palindrome (5774444775).

The spelling of 1313221644 in words is "one billion, three hundred thirteen million, two hundred twenty-one thousand, six hundred forty-four".