691624 has 8 divisors (see below), whose sum is σ = 1296810. Its totient is φ = 345808.

The previous prime is 691591. The next prime is 691631. The reversal of 691624 is 426196.

It can be written as a sum of positive squares in only one way, i.e., 669124 + 22500 = 818^2 + 150^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 691592 and 691601.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43219 + ... + 43234.

2⁶⁹¹⁶²⁴ is an apocalyptic number.

It is an amenable number.

691624 is a deficient number, since it is larger than the sum of its proper divisors (605186).

691624 is a wasteful number, since it uses less digits than its factorization.

691624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86459 (or 86455 counting only the distinct ones).

The product of its digits is 2592, while the sum is 28.

The square root of 691624 is about 831.6393449086. The cubic root of 691624 is about 88.4348313154.

The spelling of 691624 in words is "six hundred ninety-one thousand, six hundred twenty-four".