1215401144221 has 16 divisors (see below), whose sum is σ = 1336713412608. Its totient is φ = 1095921010800.

The previous prime is 1215401144197. The next prime is 1215401144257. The reversal of 1215401144221 is 1224411045121.

It is not a de Polignac number, because 1215401144221 - 2⁹ = 1215401143709 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1215401144221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215401144291) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 136036 + ... + 1565026.

It is an arithmetic number, because the mean of its divisors is an integer number (83544588288).

Almost surely, 2^{1215401144221} is an apocalyptic number.

1215401144221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1215401144221 is a deficient number, since it is larger than the sum of its proper divisors (121312268387).

1215401144221 is a wasteful number, since it uses less digits than its factorization.

1215401144221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1429632.

The product of its (nonzero) digits is 2560, while the sum is 28.

Adding to 1215401144221 its reverse (1224411045121), we get a palindrome (2439812189342).

The spelling of 1215401144221 in words is "one trillion, two hundred fifteen billion, four hundred one million, one hundred forty-four thousand, two hundred twenty-one".