1721505135513 has 8 divisors (see below), whose sum is σ = 2324395120000. Its totient is φ = 1133142620688.

The previous prime is 1721505135509. The next prime is 1721505135517. The reversal of 1721505135513 is 3155315051271.

It is an interprime number because it is at equal distance from previous prime (1721505135509) and next prime (1721505135517).

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

It is not a de Polignac number, because 1721505135513 - 2² = 1721505135509 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1721505135517) 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, 3631867138 + ... + 3631867611.

It is an arithmetic number, because the mean of its divisors is an integer number (290549390000).

Almost surely, 2^{1721505135513} is an apocalyptic number.

It is an amenable number.

1721505135513 is a deficient number, since it is larger than the sum of its proper divisors (602889984487).

1721505135513 is an equidigital number, since it uses as much as digits as its factorization.

1721505135513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7263734831.

The product of its (nonzero) digits is 78750, while the sum is 39.

The spelling of 1721505135513 in words is "one trillion, seven hundred twenty-one billion, five hundred five million, one hundred thirty-five thousand, five hundred thirteen".