668158497 has 16 divisors (see below), whose sum is σ = 1048092480. Its totient is φ = 419236416.

The previous prime is 668158481. The next prime is 668158507. The reversal of 668158497 is 794851866.

It is not a de Polignac number, because 668158497 - 2⁴ = 668158481 is a prime.

It is a super-2 number, since 2×668158497² = 892871554226598018, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (668158417) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 727383 + ... + 728300.

It is an arithmetic number, because the mean of its divisors is an integer number (65505780).

Almost surely, 2^668158497 is an apocalyptic number.

It is an amenable number.

668158497 is a deficient number, since it is larger than the sum of its proper divisors (379933983).

668158497 is a wasteful number, since it uses less digits than its factorization.

668158497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1455709 (or 1455703 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 54.

The square root of 668158497 is about 25848.7620013029. The cubic root of 668158497 is about 874.2315962067.

The spelling of 668158497 in words is "six hundred sixty-eight million, one hundred fifty-eight thousand, four hundred ninety-seven".