39561221 has 4 divisors (see below), whose sum is σ = 45212832. Its totient is φ = 33909612.

The previous prime is 39561209. The next prime is 39561259. The reversal of 39561221 is 12216593.

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 a cyclic number.

It is not a de Polignac number, because 39561221 - 2¹⁸ = 39299077 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39561281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2825795 + ... + 2825808.

It is an arithmetic number, because the mean of its divisors is an integer number (11303208).

Almost surely, 2^39561221 is an apocalyptic number.

It is an amenable number.

39561221 is a deficient number, since it is larger than the sum of its proper divisors (5651611).

39561221 is an equidigital number, since it uses as much as digits as its factorization.

39561221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5651610.

The product of its digits is 3240, while the sum is 29.

The square root of 39561221 is about 6289.7711405106. The cubic root of 39561221 is about 340.7400862527.

It can be divided in two parts, 395 and 61221, that added together give a palindrome (61616).

The spelling of 39561221 in words is "thirty-nine million, five hundred sixty-one thousand, two hundred twenty-one".