1621031223137 has 4 divisors (see below), whose sum is σ = 1621096055700. Its totient is φ = 1620966390576.

The previous prime is 1621031223043. The next prime is 1621031223139. The reversal of 1621031223137 is 7313221301261.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1418840704801 + 202190518336 = 1191151^2 + 449656^2 .

It is a cyclic number.

It is not a de Polignac number, because 1621031223137 - 2⁴⁰ = 521519595361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621031223139) 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, 32378762 + ... + 32428787.

It is an arithmetic number, because the mean of its divisors is an integer number (405274013925).

Almost surely, 2^{1621031223137} is an apocalyptic number.

It is an amenable number.

1621031223137 is a deficient number, since it is larger than the sum of its proper divisors (64832563).

1621031223137 is an equidigital number, since it uses as much as digits as its factorization.

1621031223137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64832562.

The product of its (nonzero) digits is 9072, while the sum is 32.

Adding to 1621031223137 its reverse (7313221301261), we get a palindrome (8934252524398).

The spelling of 1621031223137 in words is "one trillion, six hundred twenty-one billion, thirty-one million, two hundred twenty-three thousand, one hundred thirty-seven".