1264489521 has 4 divisors (see below), whose sum is σ = 1685986032. Its totient is φ = 842993012.

The previous prime is 1264489511. The next prime is 1264489531. The reversal of 1264489521 is 1259844621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (1264489511) and next prime (1264489531).

It is a cyclic number.

It is not a de Polignac number, because 1264489521 - 2¹¹ = 1264487473 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1264489511) 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, 210748251 + ... + 210748256.

It is an arithmetic number, because the mean of its divisors is an integer number (421496508).

Almost surely, 2^1264489521 is an apocalyptic number.

It is an amenable number.

1264489521 is a deficient number, since it is larger than the sum of its proper divisors (421496511).

1264489521 is an equidigital number, since it uses as much as digits as its factorization.

1264489521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421496510.

The product of its digits is 138240, while the sum is 42.

The square root of 1264489521 is about 35559.6614297718. The cubic root of 1264489521 is about 1081.3635956877.

The spelling of 1264489521 in words is "one billion, two hundred sixty-four million, four hundred eighty-nine thousand, five hundred twenty-one".