66621249 has 36 divisors (see below), whose sum is σ = 104501124. Its totient is φ = 40753152.

The previous prime is 66621227. The next prime is 66621259. The reversal of 66621249 is 94212666.

It can be written as a sum of positive squares in 2 ways, for example, as 41370624 + 25250625 = 6432^2 + 5025^2 .

It is not a de Polignac number, because 66621249 - 2¹² = 66617153 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66621209) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 686769 + ... + 686865.

It is an arithmetic number, because the mean of its divisors is an integer number (2902809).

Almost surely, 2^66621249 is an apocalyptic number.

It is an amenable number.

66621249 is a deficient number, since it is larger than the sum of its proper divisors (37879875).

66621249 is a wasteful number, since it uses less digits than its factorization.

66621249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254 (or 184 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 66621249 is about 8162.1840827073. The cubic root of 66621249 is about 405.3880323124.

The spelling of 66621249 in words is "sixty-six million, six hundred twenty-one thousand, two hundred forty-nine".