1221260240 has 20 divisors (see below), whose sum is σ = 2839430244. Its totient is φ = 488504064.

The previous prime is 1221260239. The next prime is 1221260323. The reversal of 1221260240 is 420621221.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 170981776 + 1050278464 = 13076^2 + 32408^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7632797 + ... + 7632956.

Almost surely, 2^1221260240 is an apocalyptic number.

1221260240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221260240 is an abundant number, since it is smaller than the sum of its proper divisors (1618170004).

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

1221260240 is a wasteful number, since it uses less digits than its factorization.

1221260240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15265766 (or 15265760 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 1221260240 is about 34946.5340198424. The cubic root of 1221260240 is about 1068.8975280996.

Adding to 1221260240 its reverse (420621221), we get a palindrome (1641881461).

The spelling of 1221260240 in words is "one billion, two hundred twenty-one million, two hundred sixty thousand, two hundred forty".