921457 has 2 divisors, whose sum is σ = 921458. Its totient is φ = 921456.

The previous prime is 921409. The next prime is 921463. The reversal of 921457 is 754129.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 516961 + 404496 = 719^2 + 636^2 .

It is a cyclic number.

It is not a de Polignac number, because 921457 - 2¹¹ = 919409 is a prime.

It is equal to p₇₂₈₃₈ and since 921457 and 72838 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (921407) 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, 460728 + 460729.

It is an arithmetic number, because the mean of its divisors is an integer number (460729).

2⁹²¹⁴⁵⁷ is an apocalyptic number.

It is an amenable number.

921457 is a deficient number, since it is larger than the sum of its proper divisors (1).

921457 is an equidigital number, since it uses as much as digits as its factorization.

921457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2520, while the sum is 28.

The square root of 921457 is about 959.9255179440. The cubic root of 921457 is about 97.3101983651.

It can be divided in two parts, 921 and 457, that added together give a triangular number (1378 = T₅₂).

The spelling of 921457 in words is "nine hundred twenty-one thousand, four hundred fifty-seven".