665551654 has 4 divisors (see below), whose sum is σ = 998327484. Its totient is φ = 332775826.

The previous prime is 665551651. The next prime is 665551673. The reversal of 665551654 is 456155566.

665551654 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 456155566 = 2 ⋅228077783.

It is a self number, because there is not a number n which added to its sum of digits gives 665551654.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665551651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166387912 + ... + 166387915.

It is an arithmetic number, because the mean of its divisors is an integer number (249581871).

Almost surely, 2^665551654 is an apocalyptic number.

665551654 is a deficient number, since it is larger than the sum of its proper divisors (332775830).

665551654 is a wasteful number, since it uses less digits than its factorization.

665551654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332775829.

The product of its digits is 540000, while the sum is 43.

The square root of 665551654 is about 25798.2878114033. The cubic root of 665551654 is about 873.0931663215.

The spelling of 665551654 in words is "six hundred sixty-five million, five hundred fifty-one thousand, six hundred fifty-four".