660349399 has 4 divisors (see below), whose sum is σ = 663089680. Its totient is φ = 657609120.

The previous prime is 660349373. The next prime is 660349429. The reversal of 660349399 is 993943066.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 993943066 = 2 ⋅496971533.

It is a cyclic number.

It is not a de Polignac number, because 660349399 - 2⁷ = 660349271 is a prime.

It is a super-2 number, since 2×660349399² = 872122657519322402, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660349499) 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, 1369779 + ... + 1370260.

It is an arithmetic number, because the mean of its divisors is an integer number (165772420).

Almost surely, 2^660349399 is an apocalyptic number.

660349399 is a deficient number, since it is larger than the sum of its proper divisors (2740281).

660349399 is a wasteful number, since it uses less digits than its factorization.

660349399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2740280.

The product of its (nonzero) digits is 944784, while the sum is 49.

The square root of 660349399 is about 25697.2644263937. The cubic root of 660349399 is about 870.8123820655.

The spelling of 660349399 in words is "six hundred sixty million, three hundred forty-nine thousand, three hundred ninety-nine".