691634688475 has 24 divisors (see below), whose sum is σ = 867371114160. Its totient is φ = 547022784000.

The previous prime is 691634688473. The next prime is 691634688487. The reversal of 691634688475 is 574886436196.

It is not a de Polignac number, because 691634688475 - 2¹ = 691634688473 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 691634688475.

It is not an unprimeable number, because it can be changed into a prime (691634688473) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25375855 + ... + 25403095.

It is an arithmetic number, because the mean of its divisors is an integer number (36140463090).

Almost surely, 2^691634688475 is an apocalyptic number.

691634688475 is a deficient number, since it is larger than the sum of its proper divisors (175736425685).

691634688475 is a wasteful number, since it uses less digits than its factorization.

691634688475 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38751 (or 38746 counting only the distinct ones).

The product of its digits is 209018880, while the sum is 67.

The spelling of 691634688475 in words is "six hundred ninety-one billion, six hundred thirty-four million, six hundred eighty-eight thousand, four hundred seventy-five".