1718249521 has 4 divisors (see below), whose sum is σ = 1718985844. Its totient is φ = 1717513200.

The previous prime is 1718249503. The next prime is 1718249531. The reversal of 1718249521 is 1259428171.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1259428171 = 14867 ⋅84713.

It can be written as a sum of positive squares in 2 ways, for example, as 763748496 + 954501025 = 27636^2 + 30895^2 .

It is a cyclic number.

It is not a de Polignac number, because 1718249521 - 2²¹ = 1716152369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1718249531) 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, 364650 + ... + 369331.

It is an arithmetic number, because the mean of its divisors is an integer number (429746461).

Almost surely, 2^1718249521 is an apocalyptic number.

It is an amenable number.

1718249521 is a deficient number, since it is larger than the sum of its proper divisors (736323).

1718249521 is an equidigital number, since it uses as much as digits as its factorization.

1718249521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 736322.

The product of its digits is 40320, while the sum is 40.

The square root of 1718249521 is about 41451.7734361270. The cubic root of 1718249521 is about 1197.7386860687.

The spelling of 1718249521 in words is "one billion, seven hundred eighteen million, two hundred forty-nine thousand, five hundred twenty-one".