691908216 has 64 divisors (see below), whose sum is σ = 1823277600. Its totient is φ = 218469888.

The previous prime is 691908209. The next prime is 691908229. The reversal of 691908216 is 612809196.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27510 + ... + 46266.

Almost surely, 2^691908216 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 691908216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (911638800).

691908216 is an abundant number, since it is smaller than the sum of its proper divisors (1131369384).

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

691908216 is a wasteful number, since it uses less digits than its factorization.

691908216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18848 (or 18844 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 42.

The square root of 691908216 is about 26304.1482660055. The cubic root of 691908216 is about 884.4694346102.

The spelling of 691908216 in words is "six hundred ninety-one million, nine hundred eight thousand, two hundred sixteen".