66158121 has 4 divisors (see below), whose sum is σ = 88210832. Its totient is φ = 44105412.

The previous prime is 66158119. The next prime is 66158137. The reversal of 66158121 is 12185166.

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 not a de Polignac number, because 66158121 - 2¹ = 66158119 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66158111) 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, 11026351 + ... + 11026356.

It is an arithmetic number, because the mean of its divisors is an integer number (22052708).

Almost surely, 2^66158121 is an apocalyptic number.

It is an amenable number.

66158121 is a deficient number, since it is larger than the sum of its proper divisors (22052711).

66158121 is a wasteful number, since it uses less digits than its factorization.

66158121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22052710.

The product of its digits is 2880, while the sum is 30.

The square root of 66158121 is about 8133.7642577100. The cubic root of 66158121 is about 404.4464744299.

The spelling of 66158121 in words is "sixty-six million, one hundred fifty-eight thousand, one hundred twenty-one".