66791941 has 4 divisors (see below), whose sum is σ = 66811500. Its totient is φ = 66772384.

The previous prime is 66791939. The next prime is 66791971. The reversal of 66791941 is 14919766.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 14919766 = 2 ⋅7459883.

It can be written as a sum of positive squares in 2 ways, for example, as 23561316 + 43230625 = 4854^2 + 6575^2 .

It is a cyclic number.

It is not a de Polignac number, because 66791941 - 2¹ = 66791939 is a prime.

It is a super-2 number, since 2×66791941² = 8922326765094962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66791971) 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, 3166 + ... + 11983.

It is an arithmetic number, because the mean of its divisors is an integer number (16702875).

Almost surely, 2^66791941 is an apocalyptic number.

It is an amenable number.

66791941 is a deficient number, since it is larger than the sum of its proper divisors (19559).

66791941 is a wasteful number, since it uses less digits than its factorization.

66791941 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19558.

The product of its digits is 81648, while the sum is 43.

The square root of 66791941 is about 8172.6336636362. The cubic root of 66791941 is about 405.7339553842.

The spelling of 66791941 in words is "sixty-six million, seven hundred ninety-one thousand, nine hundred forty-one".