66201515 has 4 divisors (see below), whose sum is σ = 79441824. Its totient is φ = 52961208.

The previous prime is 66201479. The next prime is 66201557. The reversal of 66201515 is 51510266.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51510266 = 2 ⋅25755133.

It is a cyclic number.

It is not a de Polignac number, because 66201515 - 2¹² = 66197419 is a prime.

It is a Duffinian 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, 6620147 + ... + 6620156.

It is an arithmetic number, because the mean of its divisors is an integer number (19860456).

Almost surely, 2^66201515 is an apocalyptic number.

66201515 is a deficient number, since it is larger than the sum of its proper divisors (13240309).

66201515 is a wasteful number, since it uses less digits than its factorization.

66201515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13240308.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 66201515 is about 8136.4313430398. The cubic root of 66201515 is about 404.5348823946.

The spelling of 66201515 in words is "sixty-six million, two hundred one thousand, five hundred fifteen".