691090812 has 48 divisors (see below), whose sum is σ = 1849523200. Its totient is φ = 222931440.

The previous prime is 691090747. The next prime is 691090837. The reversal of 691090812 is 218090196.

691090812 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×691090812³ (a number of 27 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 99862 + ... + 106557.

Almost surely, 2^691090812 is an apocalyptic number.

691090812 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is an amenable number.

691090812 is an abundant number, since it is smaller than the sum of its proper divisors (1158432388).

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

691090812 is a wasteful number, since it uses less digits than its factorization.

691090812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206463 (or 206455 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 691090812 is about 26288.6061250877. The cubic root of 691090812 is about 884.1210002739.

The spelling of 691090812 in words is "six hundred ninety-one million, ninety thousand, eight hundred twelve".