691863520538 has 8 divisors (see below), whose sum is σ = 1092416085120. Its totient is φ = 327724825500.

The previous prime is 691863520493. The next prime is 691863520571. The reversal of 691863520538 is 835025368196.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9103467338 + ... + 9103467413.

It is an arithmetic number, because the mean of its divisors is an integer number (136552010640).

Almost surely, 2^691863520538 is an apocalyptic number.

691863520538 is a deficient number, since it is larger than the sum of its proper divisors (400552564582).

691863520538 is a wasteful number, since it uses less digits than its factorization.

691863520538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18206934772.

The product of its (nonzero) digits is 9331200, while the sum is 56.

The spelling of 691863520538 in words is "six hundred ninety-one billion, eight hundred sixty-three million, five hundred twenty thousand, five hundred thirty-eight".