37686821 has 2 divisors, whose sum is σ = 37686822. Its totient is φ = 37686820.

The previous prime is 37686799. The next prime is 37686851. The reversal of 37686821 is 12868673.

It is a happy number.

37686821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22562500 + 15124321 = 4750^2 + 3889^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-37686821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (37686851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18843410 + 18843411.

It is an arithmetic number, because the mean of its divisors is an integer number (18843411).

Almost surely, 2^37686821 is an apocalyptic number.

It is an amenable number.

37686821 is a deficient number, since it is larger than the sum of its proper divisors (1).

37686821 is an equidigital number, since it uses as much as digits as its factorization.

37686821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 41.

The square root of 37686821 is about 6138.9592766201. The cubic root of 37686821 is about 335.2713951330.

The spelling of 37686821 in words is "thirty-seven million, six hundred eighty-six thousand, eight hundred twenty-one".