1621135333721 has 8 divisors (see below), whose sum is σ = 1657339749120. Its totient is φ = 1585002259008.

The previous prime is 1621135333651. The next prime is 1621135333787. The reversal of 1621135333721 is 1273335311261.

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

It is a cyclic number.

It is not a de Polignac number, because 1621135333721 - 2¹⁴ = 1621135317337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621135333021) 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, 17789216 + ... + 17880113.

It is an arithmetic number, because the mean of its divisors is an integer number (207167468640).

Almost surely, 2^{1621135333721} is an apocalyptic number.

It is an amenable number.

1621135333721 is a deficient number, since it is larger than the sum of its proper divisors (36204415399).

1621135333721 is an equidigital number, since it uses as much as digits as its factorization.

1621135333721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35670343.

The product of its digits is 68040, while the sum is 38.

The spelling of 1621135333721 in words is "one trillion, six hundred twenty-one billion, one hundred thirty-five million, three hundred thirty-three thousand, seven hundred twenty-one".