1221253544 has 32 divisors (see below), whose sum is σ = 2626732800. Its totient is φ = 521442240.

The previous prime is 1221253543. The next prime is 1221253547. The reversal of 1221253544 is 4453521221.

It is not an unprimeable number, because it can be changed into a prime (1221253543) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25472 + ... + 55599.

It is an arithmetic number, because the mean of its divisors is an integer number (82085400).

Almost surely, 2^1221253544 is an apocalyptic number.

1221253544 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1221253544 is an abundant number, since it is smaller than the sum of its proper divisors (1405479256).

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

1221253544 is a wasteful number, since it uses less digits than its factorization.

1221253544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81353 (or 81349 counting only the distinct ones).

The product of its digits is 9600, while the sum is 29.

The square root of 1221253544 is about 34946.4382162188. The cubic root of 1221253544 is about 1068.8955745572.

Adding to 1221253544 its reverse (4453521221), we get a palindrome (5674774765).

It can be divided in two parts, 12212 and 53544, that added together give a palindrome (65756).

The spelling of 1221253544 in words is "one billion, two hundred twenty-one million, two hundred fifty-three thousand, five hundred forty-four".