39721601 has 2 divisors, whose sum is σ = 39721602. Its totient is φ = 39721600.

The previous prime is 39721567. The next prime is 39721603. The reversal of 39721601 is 10612793.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22090000 + 17631601 = 4700^2 + 4199^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39721601 is a prime.

Together with 39721603, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (39721603) 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, 19860800 + 19860801.

It is an arithmetic number, because the mean of its divisors is an integer number (19860801).

Almost surely, 2^39721601 is an apocalyptic number.

It is an amenable number.

39721601 is a deficient number, since it is larger than the sum of its proper divisors (1).

39721601 is an equidigital number, since it uses as much as digits as its factorization.

39721601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2268, while the sum is 29.

The square root of 39721601 is about 6302.5075168539. The cubic root of 39721601 is about 341.1999154537.

The spelling of 39721601 in words is "thirty-nine million, seven hundred twenty-one thousand, six hundred one".