66861423 has 16 divisors (see below), whose sum is σ = 99208800. Its totient is φ = 44504640.

The previous prime is 66861409. The next prime is 66861491. The reversal of 66861423 is 32416866.

It is not a de Polignac number, because 66861423 - 2⁴ = 66861407 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66862423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20313 + ... + 23373.

It is an arithmetic number, because the mean of its divisors is an integer number (6200550).

Almost surely, 2^66861423 is an apocalyptic number.

66861423 is a deficient number, since it is larger than the sum of its proper divisors (32347377).

66861423 is a wasteful number, since it uses less digits than its factorization.

66861423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3879 (or 3873 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 66861423 is about 8176.8834527588. The cubic root of 66861423 is about 405.8745982840.

The spelling of 66861423 in words is "sixty-six million, eight hundred sixty-one thousand, four hundred twenty-three".