1421544215721 has 16 divisors (see below), whose sum is σ = 2166196966784. Its totient is φ = 812298098304.

The previous prime is 1421544215719. The next prime is 1421544215737. The reversal of 1421544215721 is 1275124451241.

It is not a de Polignac number, because 1421544215721 - 2¹ = 1421544215719 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 1421544215721.

It is not an unprimeable number, because it can be changed into a prime (1421544215321) 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, 909615 + ... + 1915851.

It is an arithmetic number, because the mean of its divisors is an integer number (135387310424).

Almost surely, 2^{1421544215721} is an apocalyptic number.

It is an amenable number.

1421544215721 is a deficient number, since it is larger than the sum of its proper divisors (744652751063).

1421544215721 is a wasteful number, since it uses less digits than its factorization.

1421544215721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1073520.

The product of its digits is 89600, while the sum is 39.

Adding to 1421544215721 its reverse (1275124451241), we get a palindrome (2696668666962).

The spelling of 1421544215721 in words is "one trillion, four hundred twenty-one billion, five hundred forty-four million, two hundred fifteen thousand, seven hundred twenty-one".