66651205 has 4 divisors (see below), whose sum is σ = 79981452. Its totient is φ = 53320960.

The previous prime is 66651119. The next prime is 66651253. The reversal of 66651205 is 50215666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50215666 = 2 ⋅25107833.

It can be written as a sum of positive squares in 2 ways, for example, as 22268961 + 44382244 = 4719^2 + 6662^2 .

It is not a de Polignac number, because 66651205 - 2¹¹ = 66649157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6665116 + ... + 6665125.

It is an arithmetic number, because the mean of its divisors is an integer number (19995363).

Almost surely, 2^66651205 is an apocalyptic number.

It is an amenable number.

66651205 is a deficient number, since it is larger than the sum of its proper divisors (13330247).

66651205 is a wasteful number, since it uses less digits than its factorization.

66651205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13330246.

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 66651205 is about 8164.0189245249. The cubic root of 66651205 is about 405.4487836212.

The spelling of 66651205 in words is "sixty-six million, six hundred fifty-one thousand, two hundred five".