1234664521 has 4 divisors (see below), whose sum is σ = 1257960132. Its totient is φ = 1211368912.

The previous prime is 1234664513. The next prime is 1234664537. The reversal of 1234664521 is 1254664321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1254664321 = 103 ⋅12181207.

It can be written as a sum of positive squares in 2 ways, for example, as 901200400 + 333464121 = 30020^2 + 18261^2 .

It is a cyclic number.

It is not a de Polignac number, because 1234664521 - 2³ = 1234664513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1234764521) 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, 11647726 + ... + 11647831.

It is an arithmetic number, because the mean of its divisors is an integer number (314490033).

Almost surely, 2^1234664521 is an apocalyptic number.

It is an amenable number.

1234664521 is a deficient number, since it is larger than the sum of its proper divisors (23295611).

1234664521 is an equidigital number, since it uses as much as digits as its factorization.

1234664521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23295610.

The product of its digits is 34560, while the sum is 34.

The square root of 1234664521 is about 35137.7933427812. The cubic root of 1234664521 is about 1072.7939677725.

It can be divided in two parts, 12346 and 64521, that added together give a palindrome (76867).

The spelling of 1234664521 in words is "one billion, two hundred thirty-four million, six hundred sixty-four thousand, five hundred twenty-one".