1321837923621 has 4 divisors (see below), whose sum is σ = 1762450564832. Its totient is φ = 881225282412.

The previous prime is 1321837923613. The next prime is 1321837923631. The reversal of 1321837923621 is 1263297381231.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1321837923621 - 2³ = 1321837923613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321837923631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220306320601 + ... + 220306320606.

It is an arithmetic number, because the mean of its divisors is an integer number (440612641208).

Almost surely, 2^{1321837923621} is an apocalyptic number.

It is an amenable number.

1321837923621 is a deficient number, since it is larger than the sum of its proper divisors (440612641211).

1321837923621 is an equidigital number, since it uses as much as digits as its factorization.

1321837923621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440612641210.

The product of its digits is 653184, while the sum is 48.

The spelling of 1321837923621 in words is "one trillion, three hundred twenty-one billion, eight hundred thirty-seven million, nine hundred twenty-three thousand, six hundred twenty-one".