691457 has 4 divisors (see below), whose sum is σ = 744660. Its totient is φ = 638256.

The previous prime is 691451. The next prime is 691463. The reversal of 691457 is 754196.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (691451) and next prime (691463).

It can be written as a sum of positive squares in 2 ways, for example, as 430336 + 261121 = 656^2 + 511^2 .

It is a cyclic number.

It is not a de Polignac number, because 691457 - 2¹⁰ = 690433 is a prime.

It is a super-2 number, since 2×691457² = 956225565698, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (691451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26582 + ... + 26607.

It is an arithmetic number, because the mean of its divisors is an integer number (186165).

2⁶⁹¹⁴⁵⁷ is an apocalyptic number.

It is an amenable number.

691457 is a deficient number, since it is larger than the sum of its proper divisors (53203).

691457 is a wasteful number, since it uses less digits than its factorization.

691457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53202.

The product of its digits is 7560, while the sum is 32.

The square root of 691457 is about 831.5389347469. The cubic root of 691457 is about 88.4277128976.

The spelling of 691457 in words is "six hundred ninety-one thousand, four hundred fifty-seven".