691649893 has 8 divisors (see below), whose sum is σ = 755124480. Its totient is φ = 628274880.

The previous prime is 691649891. The next prime is 691649899. The reversal of 691649893 is 398946196.

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

It is a cyclic number.

It is not a de Polignac number, because 691649893 - 2¹ = 691649891 is a prime.

It is a super-2 number, since 2×691649893² = 956759148973822898, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691649891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9973 + ... + 38506.

It is an arithmetic number, because the mean of its divisors is an integer number (94390560).

Almost surely, 2^691649893 is an apocalyptic number.

It is an amenable number.

691649893 is a deficient number, since it is larger than the sum of its proper divisors (63474587).

691649893 is a wasteful number, since it uses less digits than its factorization.

691649893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49787.

The product of its digits is 2519424, while the sum is 55.

The square root of 691649893 is about 26299.2374984523. The cubic root of 691649893 is about 884.3593490852.

The spelling of 691649893 in words is "six hundred ninety-one million, six hundred forty-nine thousand, eight hundred ninety-three".