666023623 has 16 divisors (see below), whose sum is σ = 698858496. Its totient is φ = 633971520.

The previous prime is 666023563. The next prime is 666023653. The reversal of 666023623 is 326320666.

It is a cyclic number.

It is not a de Polignac number, because 666023623 - 2¹³ = 666015431 is a prime.

It is a super-2 number, since 2×666023623² = 887174932788092258, 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 (666023653) 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, 804936 + ... + 805762.

It is an arithmetic number, because the mean of its divisors is an integer number (43678656).

Almost surely, 2^666023623 is an apocalyptic number.

666023623 is a deficient number, since it is larger than the sum of its proper divisors (32834873).

666023623 is a wasteful number, since it uses less digits than its factorization.

666023623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1254.

The product of its (nonzero) digits is 46656, while the sum is 34.

The square root of 666023623 is about 25807.4334833978. The cubic root of 666023623 is about 873.2994991878.

It can be divided in two parts, 66602 and 3623, that added together give a square (70225 = 265²).

The spelling of 666023623 in words is "six hundred sixty-six million, twenty-three thousand, six hundred twenty-three".