666956199 has 48 divisors (see below), whose sum is σ = 1118029920. Its totient is φ = 350542080.

The previous prime is 666956197. The next prime is 666956201. The reversal of 666956199 is 991659666.

It is an interprime number because it is at equal distance from previous prime (666956197) and next prime (666956201).

It is not a de Polignac number, because 666956199 - 2¹ = 666956197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666956197) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 804117 + ... + 804945.

It is an arithmetic number, because the mean of its divisors is an integer number (23292290).

Almost surely, 2^666956199 is an apocalyptic number.

666956199 is a deficient number, since it is larger than the sum of its proper divisors (451073721).

666956199 is a wasteful number, since it uses less digits than its factorization.

666956199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1280 (or 1273 counting only the distinct ones).

The product of its digits is 4723920, while the sum is 57.

The square root of 666956199 is about 25825.4951356213. The cubic root of 666956199 is about 873.7069113280.

It can be divided in two parts, 6669 and 56199, that multiplied together give a triangular number (374791131 = T₂₇₃₇₈).

The spelling of 666956199 in words is "six hundred sixty-six million, nine hundred fifty-six thousand, one hundred ninety-nine".