691264 has 28 divisors (see below), whose sum is σ = 1568704. Its totient is φ = 296064.

The previous prime is 691241. The next prime is 691267. The reversal of 691264 is 462196.

It is a tau number, because it is divible by the number of its divisors (28).

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (691267) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 324 + ... + 1219.

2⁶⁹¹²⁶⁴ is an apocalyptic number.

691264 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

691264 is an abundant number, since it is smaller than the sum of its proper divisors (877440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

691264 is a wasteful number, since it uses less digits than its factorization.

691264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1562 (or 1552 counting only the distinct ones).

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

The square root of 691264 is about 831.4228767601. The cubic root of 691264 is about 88.4194847954.

The spelling of 691264 in words is "six hundred ninety-one thousand, two hundred sixty-four".