3720545721 has 24 divisors (see below), whose sum is σ = 5414408064. Its totient is φ = 2461842720.

The previous prime is 3720545701. The next prime is 3720545747. The reversal of 3720545721 is 1275450273.

3720545721 is a `hidden beast` number, since 37 + 2 + 0 + 54 + 572 + 1 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-3720545721 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3720545701) 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 in 23 ways as a sum of consecutive naturals, for example, 672850 + ... + 678356.

It is an arithmetic number, because the mean of its divisors is an integer number (225600336).

Almost surely, 2^3720545721 is an apocalyptic number.

It is an amenable number.

3720545721 is a deficient number, since it is larger than the sum of its proper divisors (1693862343).

3720545721 is a wasteful number, since it uses less digits than its factorization.

3720545721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6061 (or 6058 counting only the distinct ones).

The product of its (nonzero) digits is 58800, while the sum is 36.

The square root of 3720545721 is about 60996.2762879834. The cubic root of 3720545721 is about 1549.5379435784.

Adding to 3720545721 its reverse (1275450273), we get a palindrome (4995995994).

The spelling of 3720545721 in words is "three billion, seven hundred twenty million, five hundred forty-five thousand, seven hundred twenty-one".