691412608 has 16 divisors (see below), whose sum is σ = 1377423810. Its totient is φ = 345706240.

The previous prime is 691412587. The next prime is 691412611. The reversal of 691412608 is 806214196.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 406748224 + 284664384 = 20168^2 + 16872^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2700703 + ... + 2700958.

Almost surely, 2^691412608 is an apocalyptic number.

It is an amenable number.

691412608 is a deficient number, since it is larger than the sum of its proper divisors (686011202).

691412608 is an equidigital number, since it uses as much as digits as its factorization.

691412608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5401675 (or 5401663 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 691412608 is about 26294.7258590007. The cubic root of 691412608 is about 884.2582048444.

The spelling of 691412608 in words is "six hundred ninety-one million, four hundred twelve thousand, six hundred eight".