1353686921 has 4 divisors (see below), whose sum is σ = 1390273092. Its totient is φ = 1317100752.

The previous prime is 1353686881. The next prime is 1353686959. The reversal of 1353686921 is 1296863531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1296863531 = 43 ⋅30159617.

It can be written as a sum of positive squares in 2 ways, for example, as 544568896 + 809118025 = 23336^2 + 28445^2 .

It is a cyclic number.

It is not a de Polignac number, because 1353686921 - 2⁶ = 1353686857 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1353686981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18293030 + ... + 18293103.

It is an arithmetic number, because the mean of its divisors is an integer number (347568273).

Almost surely, 2^1353686921 is an apocalyptic number.

It is an amenable number.

1353686921 is a deficient number, since it is larger than the sum of its proper divisors (36586171).

1353686921 is an equidigital number, since it uses as much as digits as its factorization.

1353686921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36586170.

The product of its digits is 233280, while the sum is 44.

The square root of 1353686921 is about 36792.4845722601. The cubic root of 1353686921 is about 1106.2146634270.

The spelling of 1353686921 in words is "one billion, three hundred fifty-three million, six hundred eighty-six thousand, nine hundred twenty-one".