1321563635421 has 8 divisors (see below), whose sum is σ = 1779192467520. Its totient is φ = 872488613472.

The previous prime is 1321563635377. The next prime is 1321563635423. The reversal of 1321563635421 is 1245363651231.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1321563635421 - 2²³ = 1321555246813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321563635423) 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, 2138452176 + ... + 2138452793.

It is an arithmetic number, because the mean of its divisors is an integer number (222399058440).

Almost surely, 2^{1321563635421} is an apocalyptic number.

It is an amenable number.

1321563635421 is a deficient number, since it is larger than the sum of its proper divisors (457628832099).

1321563635421 is a wasteful number, since it uses less digits than its factorization.

1321563635421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4276905075.

The product of its digits is 388800, while the sum is 42.

The spelling of 1321563635421 in words is "one trillion, three hundred twenty-one billion, five hundred sixty-three million, six hundred thirty-five thousand, four hundred twenty-one".