1263157321 has 8 divisors (see below), whose sum is σ = 1331371080. Its totient is φ = 1196587392.

The previous prime is 1263157283. The next prime is 1263157327. The reversal of 1263157321 is 1237513621.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 205606921 + 1057550400 = 14339^2 + 32520^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1263157321 - 2⁹ = 1263156809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1263157327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 409380 + ... + 412453.

It is an arithmetic number, because the mean of its divisors is an integer number (166421385).

Almost surely, 2^1263157321 is an apocalyptic number.

It is an amenable number.

1263157321 is a deficient number, since it is larger than the sum of its proper divisors (68213759).

1263157321 is an equidigital number, since it uses as much as digits as its factorization.

1263157321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 821915.

The product of its digits is 7560, while the sum is 31.

The square root of 1263157321 is about 35540.9245940507. The cubic root of 1263157321 is about 1080.9837062105.

The spelling of 1263157321 in words is "one billion, two hundred sixty-three million, one hundred fifty-seven thousand, three hundred twenty-one".