691720340 has 48 divisors (see below), whose sum is σ = 1491073920. Its totient is φ = 269458560.

The previous prime is 691720339. The next prime is 691720397. The reversal of 691720340 is 43027196.

It is a junction number, because it is equal to n+sod(n) for n = 691720297 and 691720306.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 114926 + ... + 120794.

It is an arithmetic number, because the mean of its divisors is an integer number (31064040).

Almost surely, 2^691720340 is an apocalyptic number.

It is an amenable number.

691720340 is an abundant number, since it is smaller than the sum of its proper divisors (799353580).

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

691720340 is a wasteful number, since it uses less digits than its factorization.

691720340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6032 (or 6030 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 691720340 is about 26300.5767997586. The cubic root of 691720340 is about 884.3893731136.

The spelling of 691720340 in words is "six hundred ninety-one million, seven hundred twenty thousand, three hundred forty".