691289481 has 4 divisors (see below), whose sum is σ = 921719312. Its totient is φ = 460859652.

The previous prime is 691289453. The next prime is 691289503. The reversal of 691289481 is 184982196.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 691289481 - 2¹³ = 691281289 is a prime.

It is a super-2 number, since 2×691289481² = 955762293082498722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 691289481.

It is not an unprimeable number, because it can be changed into a prime (691289281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115214911 + ... + 115214916.

It is an arithmetic number, because the mean of its divisors is an integer number (230429828).

Almost surely, 2^691289481 is an apocalyptic number.

It is an amenable number.

691289481 is a deficient number, since it is larger than the sum of its proper divisors (230429831).

691289481 is a wasteful number, since it uses less digits than its factorization.

691289481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230429830.

The product of its digits is 248832, while the sum is 48.

The square root of 691289481 is about 26292.3844677504. The cubic root of 691289481 is about 884.2057120578.

The spelling of 691289481 in words is "six hundred ninety-one million, two hundred eighty-nine thousand, four hundred eighty-one".