1321957813 has 12 divisors (see below), whose sum is σ = 1522037088. Its totient is φ = 1138524840.

The previous prime is 1321957801. The next prime is 1321957817. The reversal of 1321957813 is 3187591231.

It is not a de Polignac number, because 1321957813 - 2¹³ = 1321949621 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321957817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 162481 + ... + 170422.

It is an arithmetic number, because the mean of its divisors is an integer number (126836424).

Almost surely, 2^1321957813 is an apocalyptic number.

It is an amenable number.

1321957813 is a deficient number, since it is larger than the sum of its proper divisors (200079275).

1321957813 is a wasteful number, since it uses less digits than its factorization.

1321957813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332952 (or 332933 counting only the distinct ones).

The product of its digits is 45360, while the sum is 40.

The square root of 1321957813 is about 36358.7377806216. The cubic root of 1321957813 is about 1097.5033772033.

The spelling of 1321957813 in words is "one billion, three hundred twenty-one million, nine hundred fifty-seven thousand, eight hundred thirteen".