1221402444400 has 30 divisors (see below), whose sum is σ = 2934419373632. Its totient is φ = 488560977600.

The previous prime is 1221402444389. The next prime is 1221402444403. The reversal of 1221402444400 is 44442041221.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221402444403) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1526752656 + ... + 1526753455.

Almost surely, 2^{1221402444400} is an apocalyptic number.

1221402444400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221402444400 is an abundant number, since it is smaller than the sum of its proper divisors (1713016929232).

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

1221402444400 is a wasteful number, since it uses less digits than its factorization.

1221402444400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3053506129 (or 3053506118 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 28.

Adding to 1221402444400 its reverse (44442041221), we get a palindrome (1265844485621).

The spelling of 1221402444400 in words is "one trillion, two hundred twenty-one billion, four hundred two million, four hundred forty-four thousand, four hundred".