37681221 has 4 divisors (see below), whose sum is σ = 50241632. Its totient is φ = 25120812.

The previous prime is 37681219. The next prime is 37681229. The reversal of 37681221 is 12218673.

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 37681221 - 2¹ = 37681219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (37681229) 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, 6280201 + ... + 6280206.

It is an arithmetic number, because the mean of its divisors is an integer number (12560408).

Almost surely, 2^37681221 is an apocalyptic number.

It is an amenable number.

37681221 is a deficient number, since it is larger than the sum of its proper divisors (12560411).

37681221 is a wasteful number, since it uses less digits than its factorization.

37681221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12560410.

The product of its digits is 4032, while the sum is 30.

The square root of 37681221 is about 6138.5031563077. The cubic root of 37681221 is about 335.2547879764.

Adding to 37681221 its reverse (12218673), we get a palindrome (49899894).

The spelling of 37681221 in words is "thirty-seven million, six hundred eighty-one thousand, two hundred twenty-one".