666355453651 has 4 divisors (see below), whose sum is σ = 681852092152. Its totient is φ = 650858815152.

The previous prime is 666355453633. The next prime is 666355453661. The reversal of 666355453651 is 156354553666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 156354553666 = 2 ⋅78177276833.

It is a cyclic number.

It is not a de Polignac number, because 666355453651 - 2²⁵ = 666321899219 is a prime.

It is a super-2 number, since 2×666355453651² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 666355453592 and 666355453601.

It is not an unprimeable number, because it can be changed into a prime (666355453661) 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, 7748319186 + ... + 7748319271.

It is an arithmetic number, because the mean of its divisors is an integer number (170463023038).

Almost surely, 2^666355453651 is an apocalyptic number.

666355453651 is a deficient number, since it is larger than the sum of its proper divisors (15496638501).

666355453651 is a wasteful number, since it uses less digits than its factorization.

666355453651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15496638500.

The product of its digits is 29160000, while the sum is 55.

The spelling of 666355453651 in words is "six hundred sixty-six billion, three hundred fifty-five million, four hundred fifty-three thousand, six hundred fifty-one".