1621554730073 has 8 divisors (see below), whose sum is σ = 1626918288840. Its totient is φ = 1616197300480.

The previous prime is 1621554730051. The next prime is 1621554730079. The reversal of 1621554730073 is 3700374551261.

It can be written as a sum of positive squares in 4 ways, for example, as 157048141849 + 1464506588224 = 396293^2 + 1210168^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1621554730073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621554730079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1001990 + ... + 2060847.

It is an arithmetic number, because the mean of its divisors is an integer number (203364786105).

Almost surely, 2^{1621554730073} is an apocalyptic number.

It is an amenable number.

1621554730073 is a deficient number, since it is larger than the sum of its proper divisors (5363558767).

1621554730073 is a wasteful number, since it uses less digits than its factorization.

1621554730073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3064587.

The product of its (nonzero) digits is 529200, while the sum is 44.

The spelling of 1621554730073 in words is "one trillion, six hundred twenty-one billion, five hundred fifty-four million, seven hundred thirty thousand, seventy-three".