38340721 has 2 divisors, whose sum is σ = 38340722. Its totient is φ = 38340720.

The previous prime is 38340713. The next prime is 38340739. The reversal of 38340721 is 12704383.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32035600 + 6305121 = 5660^2 + 2511^2 .

It is a cyclic number.

It is not a de Polignac number, because 38340721 - 2³ = 38340713 is a prime.

It is equal to p_2338633 and since 38340721 and 2338633 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 38340721.

It is not a weakly prime, because it can be changed into another prime (38340751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19170360 + 19170361.

It is an arithmetic number, because the mean of its divisors is an integer number (19170361).

Almost surely, 2^38340721 is an apocalyptic number.

It is an amenable number.

38340721 is a deficient number, since it is larger than the sum of its proper divisors (1).

38340721 is an equidigital number, since it uses as much as digits as its factorization.

38340721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 38340721 is about 6191.9884528316. The cubic root of 38340721 is about 337.1993730836.

The spelling of 38340721 in words is "thirty-eight million, three hundred forty thousand, seven hundred twenty-one".