690878478481 has 3 divisors (see below), whose sum is σ = 690879309673. Its totient is φ = 690877647290.

The previous prime is 690878478467. The next prime is 690878478527. The reversal of 690878478481 is 184874878096.

The square root of 690878478481 is 831191.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 690878478481 - 2¹⁵ = 690878445713 is a prime.

It is a super-2 number, since 2×690878478481² (a number of 24 digits) 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 690878478481.

It is not an unprimeable number, because it can be changed into a prime (690878478281) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 415596 + ... + 1246786.

Almost surely, 2^690878478481 is an apocalyptic number.

690878478481 is the 831191-st square number.

690878478481 is the 415596-th centered octagonal number.

It is an amenable number.

690878478481 is a deficient number, since it is larger than the sum of its proper divisors (831192).

690878478481 is an frugal number, since it uses more digits than its factorization.

690878478481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1662382 (or 831191 counting only the distinct ones).

The product of its (nonzero) digits is 173408256, while the sum is 70.

The spelling of 690878478481 in words is "six hundred ninety billion, eight hundred seventy-eight million, four hundred seventy-eight thousand, four hundred eighty-one".