37720321 has 2 divisors, whose sum is σ = 37720322. Its totient is φ = 37720320.

The previous prime is 37720313. The next prime is 37720343. The reversal of 37720321 is 12302773.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35283600 + 2436721 = 5940^2 + 1561^2 .

It is a cyclic number.

It is not a de Polignac number, because 37720321 - 2³ = 37720313 is a prime.

It is not a weakly prime, because it can be changed into another prime (37720721) 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 as a sum of consecutive naturals, namely, 18860160 + 18860161.

It is an arithmetic number, because the mean of its divisors is an integer number (18860161).

Almost surely, 2^37720321 is an apocalyptic number.

It is an amenable number.

37720321 is a deficient number, since it is larger than the sum of its proper divisors (1).

37720321 is an equidigital number, since it uses as much as digits as its factorization.

37720321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1764, while the sum is 25.

The square root of 37720321 is about 6141.6871460536. The cubic root of 37720321 is about 335.3707071750.

The spelling of 37720321 in words is "thirty-seven million, seven hundred twenty thousand, three hundred twenty-one".