66142261 has 4 divisors (see below), whose sum is σ = 66160224. Its totient is φ = 66124300.

The previous prime is 66142259. The next prime is 66142289. The reversal of 66142261 is 16224166.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66142261 - 2¹ = 66142259 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 (66142201) 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, 1225 + ... + 11566.

It is an arithmetic number, because the mean of its divisors is an integer number (16540056).

Almost surely, 2^66142261 is an apocalyptic number.

It is an amenable number.

66142261 is a deficient number, since it is larger than the sum of its proper divisors (17963).

66142261 is a wasteful number, since it uses less digits than its factorization.

66142261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17962.

The product of its digits is 3456, while the sum is 28.

The square root of 66142261 is about 8132.7892509274. The cubic root of 66142261 is about 404.4141527051.

The spelling of 66142261 in words is "sixty-six million, one hundred forty-two thousand, two hundred sixty-one".