3657105721 has 2 divisors, whose sum is σ = 3657105722. Its totient is φ = 3657105720.

The previous prime is 3657105713. The next prime is 3657105787. The reversal of 3657105721 is 1275017563.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2609677225 + 1047428496 = 51085^2 + 32364^2 .

It is a cyclic number.

It is not a de Polignac number, because 3657105721 - 2³ = 3657105713 is a prime.

It is not a weakly prime, because it can be changed into another prime (3657105791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1828552860 + 1828552861.

It is an arithmetic number, because the mean of its divisors is an integer number (1828552861).

Almost surely, 2^3657105721 is an apocalyptic number.

It is an amenable number.

3657105721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3657105721 is an equidigital number, since it uses as much as digits as its factorization.

3657105721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 44100, while the sum is 37.

The square root of 3657105721 is about 60474.0086400761. The cubic root of 3657105721 is about 1540.6802135064.

The spelling of 3657105721 in words is "three billion, six hundred fifty-seven million, one hundred five thousand, seven hundred twenty-one".