691999028 has 12 divisors (see below), whose sum is σ = 1383998112. Its totient is φ = 296571000.

The previous prime is 691999027. The next prime is 691999039. The reversal of 691999028 is 820999196.

691999028 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691999027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12357098 + ... + 12357153.

It is an arithmetic number, because the mean of its divisors is an integer number (115333176).

Almost surely, 2^691999028 is an apocalyptic number.

It is an amenable number.

691999028 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

691999028 is a wasteful number, since it uses less digits than its factorization.

691999028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24714262 (or 24714260 counting only the distinct ones).

The product of its (nonzero) digits is 629856, while the sum is 53.

The square root of 691999028 is about 26305.8744009774. The cubic root of 691999028 is about 884.5081280490.

The spelling of 691999028 in words is "six hundred ninety-one million, nine hundred ninety-nine thousand, twenty-eight".