1310921 has 8 divisors (see below), whose sum is σ = 1412640. Its totient is φ = 1211968.

The previous prime is 1310899. The next prime is 1310923. The reversal of 1310921 is 1290131.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1310921 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 self number, because there is not a number n which added to its sum of digits gives 1310921.

It is not an unprimeable number, because it can be changed into a prime (1310923) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 350 + ... + 1656.

It is an arithmetic number, because the mean of its divisors is an integer number (176580).

2^1310921 is an apocalyptic number.

It is an amenable number.

1310921 is a deficient number, since it is larger than the sum of its proper divisors (101719).

1310921 is a wasteful number, since it uses less digits than its factorization.

1310921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1383.

The product of its (nonzero) digits is 54, while the sum is 17.

The square root of 1310921 is about 1144.9545842521. The cubic root of 1310921 is about 109.4440544610. Note that the first 3 decimals are identical.

The spelling of 1310921 in words is "one million, three hundred ten thousand, nine hundred twenty-one".