1357921 has 8 divisors (see below), whose sum is σ = 1399464. Its totient is φ = 1317120.

The previous prime is 1357919. The next prime is 1357927. The reversal of 1357921 is 1297531.

It can be written as a sum of positive squares in 4 ways, for example, as 10000 + 1347921 = 100^2 + 1161^2 .

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 1357921 - 2¹ = 1357919 is a prime.

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 1357921.

It is not an unprimeable number, because it can be changed into a prime (1357927) 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, 6795 + ... + 6991.

It is an arithmetic number, because the mean of its divisors is an integer number (174933).

2^1357921 is an apocalyptic number.

It is an amenable number.

1357921 is a deficient number, since it is larger than the sum of its proper divisors (41543).

1357921 is a wasteful number, since it uses less digits than its factorization.

1357921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371.

The product of its digits is 1890, while the sum is 28.

The square root of 1357921 is about 1165.2986741604. The cubic root of 1357921 is about 110.7366807083.

It can be divided in two parts, 1357 and 921, that added together give a triangular number (2278 = T₆₇).

The spelling of 1357921 in words is "one million, three hundred fifty-seven thousand, nine hundred twenty-one".