66221541 has 24 divisors (see below), whose sum is σ = 97830720. Its totient is φ = 43152000.

The previous prime is 66221537. The next prime is 66221567. The reversal of 66221541 is 14512266.

It is not a de Polignac number, because 66221541 - 2² = 66221537 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66221041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 164941 + ... + 165341.

It is an arithmetic number, because the mean of its divisors is an integer number (4076280).

Almost surely, 2^66221541 is an apocalyptic number.

It is an amenable number.

66221541 is a deficient number, since it is larger than the sum of its proper divisors (31609179).

66221541 is a wasteful number, since it uses less digits than its factorization.

66221541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 777 (or 774 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 66221541 is about 8137.6618877906. The cubic root of 66221541 is about 404.5756689679.

The spelling of 66221541 in words is "sixty-six million, two hundred twenty-one thousand, five hundred forty-one".