1621323513203 has 4 divisors (see below), whose sum is σ = 1691815839888. Its totient is φ = 1550831186520.

The previous prime is 1621323513193. The next prime is 1621323513211. The reversal of 1621323513203 is 3023153231261.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1621323513203 is a prime.

It is a super-4 number, since 4×1621323513203⁴ (a number of 50 digits) contains 4444 as substring.

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 1621323513203.

It is not an unprimeable number, because it can be changed into a prime (1621323513233) 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, 35246163308 + ... + 35246163353.

It is an arithmetic number, because the mean of its divisors is an integer number (422953959972).

Almost surely, 2^{1621323513203} is an apocalyptic number.

1621323513203 is a deficient number, since it is larger than the sum of its proper divisors (70492326685).

1621323513203 is an equidigital number, since it uses as much as digits as its factorization.

1621323513203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70492326684.

The product of its (nonzero) digits is 19440, while the sum is 32.

Adding to 1621323513203 its reverse (3023153231261), we get a palindrome (4644476744464).

The spelling of 1621323513203 in words is "one trillion, six hundred twenty-one billion, three hundred twenty-three million, five hundred thirteen thousand, two hundred three".