1921457 has 2 divisors, whose sum is σ = 1921458. Its totient is φ = 1921456.

The previous prime is 1921427. The next prime is 1921477. The reversal of 1921457 is 7541291.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1597696 + 323761 = 1264^2 + 569^2 .

It is a cyclic number.

It is not a de Polignac number, because 1921457 - 2⁶ = 1921393 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1921417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960728 + 960729.

It is an arithmetic number, because the mean of its divisors is an integer number (960729).

2^1921457 is an apocalyptic number.

It is an amenable number.

1921457 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921457 is an equidigital number, since it uses as much as digits as its factorization.

1921457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2520, while the sum is 29.

The square root of 1921457 is about 1386.1662959400. The cubic root of 1921457 is about 124.3207314400.

The spelling of 1921457 in words is "one million, nine hundred twenty-one thousand, four hundred fifty-seven".