669867481 has 4 divisors (see below), whose sum is σ = 669940132. Its totient is φ = 669794832.

The previous prime is 669867467. The next prime is 669867487. The reversal of 669867481 is 184768966.

It is a happy 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 can be written as a sum of positive squares in 2 ways, for example, as 340771600 + 329095881 = 18460^2 + 18141^2 .

It is a cyclic number.

It is not a de Polignac number, because 669867481 - 2⁵ = 669867449 is a prime.

It is a super-2 number, since 2×669867481² = 897444884202570722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (669867487) 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, 20070 + ... + 41743.

It is an arithmetic number, because the mean of its divisors is an integer number (167485033).

Almost surely, 2^669867481 is an apocalyptic number.

It is an amenable number.

669867481 is a deficient number, since it is larger than the sum of its proper divisors (72651).

669867481 is a wasteful number, since it uses less digits than its factorization.

669867481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72650.

The product of its digits is 3483648, while the sum is 55.

The square root of 669867481 is about 25881.7982566900. The cubic root of 669867481 is about 874.9763176175.

The spelling of 669867481 in words is "six hundred sixty-nine million, eight hundred sixty-seven thousand, four hundred eighty-one".