669158551 has 4 divisors (see below), whose sum is σ = 669218872. Its totient is φ = 669098232.

The previous prime is 669158543. The next prime is 669158563. The reversal of 669158551 is 155851966.

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, and also an emirpimes, since its reverse is a distinct semiprime: 155851966 = 2 ⋅77925983.

It is a cyclic number.

It is not a de Polignac number, because 669158551 - 2³ = 669158543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669158531) 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, 8181 + ... + 37486.

It is an arithmetic number, because the mean of its divisors is an integer number (167304718).

Almost surely, 2^669158551 is an apocalyptic number.

669158551 is a deficient number, since it is larger than the sum of its proper divisors (60321).

669158551 is a wasteful number, since it uses less digits than its factorization.

669158551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60320.

The product of its digits is 324000, while the sum is 46.

The square root of 669158551 is about 25868.0990990834. The cubic root of 669158551 is about 874.6675421606.

It can be divided in two parts, 66915 and 8551, that added together give a triangular number (75466 = T₃₈₈).

The spelling of 669158551 in words is "six hundred sixty-nine million, one hundred fifty-eight thousand, five hundred fifty-one".