691477440 has 56 divisors (see below), whose sum is σ = 2195443920. Its totient is φ = 184393728.

The previous prime is 691477427. The next prime is 691477447. The reversal of 691477440 is 44774196.

It is a junction number, because it is equal to n+sod(n) for n = 691477392 and 691477401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691477447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 359185 + ... + 361104.

Almost surely, 2^691477440 is an apocalyptic number.

691477440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

691477440 is an abundant number, since it is smaller than the sum of its proper divisors (1503966480).

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

691477440 is a wasteful number, since it uses less digits than its factorization.

691477440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720309 (or 720299 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 42.

The square root of 691477440 is about 26295.9586248534. The cubic root of 691477440 is about 884.2858421941.

The spelling of 691477440 in words is "six hundred ninety-one million, four hundred seventy-seven thousand, four hundred forty".