691404127 has 16 divisors (see below), whose sum is σ = 765683712. Its totient is φ = 620991360.

The previous prime is 691404121. The next prime is 691404137. The reversal of 691404127 is 721404196.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-691404127 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 691404092 and 691404101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691404121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 188602 + ... + 192232.

It is an arithmetic number, because the mean of its divisors is an integer number (47855232).

Almost surely, 2^691404127 is an apocalyptic number.

691404127 is a deficient number, since it is larger than the sum of its proper divisors (74279585).

691404127 is a wasteful number, since it uses less digits than its factorization.

691404127 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4158.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 691404127 is about 26294.5645904244. The cubic root of 691404127 is about 884.2545893359.

The spelling of 691404127 in words is "six hundred ninety-one million, four hundred four thousand, one hundred twenty-seven".