691491456 has 288 divisors, whose sum is σ = 2214526080. Its totient is φ = 206807040.

The previous prime is 691491433. The next prime is 691491461. The reversal of 691491456 is 654194196.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (288).

Its product of digits (233280) is a multiple of the sum of its prime divisors (120).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 10320735 + ... + 10320801.

Almost surely, 2^691491456 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 691491456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1107263040).

691491456 is an abundant number, since it is smaller than the sum of its proper divisors (1523034624).

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

691491456 is a wasteful number, since it uses less digits than its factorization.

691491456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152 (or 120 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The square root of 691491456 is about 26296.2251283335. The cubic root of 691491456 is about 884.2918168728.

The spelling of 691491456 in words is "six hundred ninety-one million, four hundred ninety-one thousand, four hundred fifty-six".