1340321021 has 24 divisors (see below), whose sum is σ = 1600093824. Its totient is φ = 1113742080.

The previous prime is 1340320981. The next prime is 1340321023. The reversal of 1340321021 is 1201230431.

It is not a de Polignac number, because 1340321021 - 2⁶ = 1340320957 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1340321023) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 78656 + ... + 94166.

It is an arithmetic number, because the mean of its divisors is an integer number (66670576).

Almost surely, 2^1340321021 is an apocalyptic number.

It is an amenable number.

1340321021 is a deficient number, since it is larger than the sum of its proper divisors (259772803).

1340321021 is a wasteful number, since it uses less digits than its factorization.

1340321021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15581 (or 15564 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 1340321021 is about 36610.3949855775. The cubic root of 1340321021 is about 1102.5618035328.

Adding to 1340321021 its reverse (1201230431), we get a palindrome (2541551452).

The spelling of 1340321021 in words is "one billion, three hundred forty million, three hundred twenty-one thousand, twenty-one".