668598149 has 4 divisors (see below), whose sum is σ = 668849664. Its totient is φ = 668346636.

The previous prime is 668598143. The next prime is 668598157. The reversal of 668598149 is 941895866.

It is a happy number.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668598149 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 668598094 and 668598103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668598143) 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, 121727 + ... + 127100.

It is an arithmetic number, because the mean of its divisors is an integer number (167212416).

Almost surely, 2^668598149 is an apocalyptic number.

It is an amenable number.

668598149 is a deficient number, since it is larger than the sum of its proper divisors (251515).

668598149 is a wasteful number, since it uses less digits than its factorization.

668598149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251514.

The product of its digits is 3732480, while the sum is 56.

The square root of 668598149 is about 25857.2649172336. The cubic root of 668598149 is about 874.4233039123.

The spelling of 668598149 in words is "six hundred sixty-eight million, five hundred ninety-eight thousand, one hundred forty-nine".