66551653 has 6 divisors (see below), whose sum is σ = 77417286. Its totient is φ = 57044232.

The previous prime is 66551647. The next prime is 66551657. The reversal of 66551653 is 35615566.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 55681444 + 10870209 = 7462^2 + 3297^2 .

It is a de Polignac number, because none of the positive numbers 2^k-66551653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66551657) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 679050 + ... + 679147.

It is an arithmetic number, because the mean of its divisors is an integer number (12902881).

Almost surely, 2^66551653 is an apocalyptic number.

It is an amenable number.

66551653 is a deficient number, since it is larger than the sum of its proper divisors (10865633).

66551653 is a wasteful number, since it uses less digits than its factorization.

66551653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1358211 (or 1358204 counting only the distinct ones).

The product of its digits is 81000, while the sum is 37.

The square root of 66551653 is about 8157.9196490282. The cubic root of 66551653 is about 405.2468200315.

The spelling of 66551653 in words is "sixty-six million, five hundred fifty-one thousand, six hundred fifty-three".