1221333544 has 8 divisors (see below), whose sum is σ = 2290000410. Its totient is φ = 610666768.

The previous prime is 1221333541. The next prime is 1221333563. The reversal of 1221333544 is 4453331221.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 677977444 + 543356100 = 26038^2 + 23310^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (1221333541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 76333339 + ... + 76333354.

Almost surely, 2^1221333544 is an apocalyptic number.

It is an amenable number.

1221333544 is a deficient number, since it is larger than the sum of its proper divisors (1068666866).

1221333544 is a wasteful number, since it uses less digits than its factorization.

1221333544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152666699 (or 152666695 counting only the distinct ones).

The product of its digits is 8640, while the sum is 28.

The square root of 1221333544 is about 34947.5828062543. The cubic root of 1221333544 is about 1068.9189139037.

Adding to 1221333544 its reverse (4453331221), we get a palindrome (5674664765).

The spelling of 1221333544 in words is "one billion, two hundred twenty-one million, three hundred thirty-three thousand, five hundred forty-four".