1321047921 has 16 divisors (see below), whose sum is σ = 1808735040. Its totient is φ = 857134080.

The previous prime is 1321047907. The next prime is 1321047943. The reversal of 1321047921 is 1297401231.

It is a de Polignac number, because none of the positive numbers 2^k-1321047921 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1321047421) 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 15 ways as a sum of consecutive naturals, for example, 38721 + ... + 64353.

It is an arithmetic number, because the mean of its divisors is an integer number (113045940).

Almost surely, 2^1321047921 is an apocalyptic number.

It is an amenable number.

1321047921 is a deficient number, since it is larger than the sum of its proper divisors (487687119).

1321047921 is a wasteful number, since it uses less digits than its factorization.

1321047921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26096.

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 1321047921 is about 36346.2229261859. Note that the first 3 decimals coincide. The cubic root of 1321047921 is about 1097.2515187521.

The spelling of 1321047921 in words is "one billion, three hundred twenty-one million, forty-seven thousand, nine hundred twenty-one".