691942406 has 8 divisors (see below), whose sum is σ = 1043182800. Its totient is φ = 344214808.

The previous prime is 691942397. The next prime is 691942409. The reversal of 691942406 is 604249196.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691942409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 877706 + ... + 878493.

It is an arithmetic number, because the mean of its divisors is an integer number (130397850).

Almost surely, 2^691942406 is an apocalyptic number.

691942406 is a deficient number, since it is larger than the sum of its proper divisors (351240394).

691942406 is a wasteful number, since it uses less digits than its factorization.

691942406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1756398.

The product of its (nonzero) digits is 93312, while the sum is 41.

The square root of 691942406 is about 26304.7981554697. The cubic root of 691942406 is about 884.4840027814.

The spelling of 691942406 in words is "six hundred ninety-one million, nine hundred forty-two thousand, four hundred six".