1371473721 has 16 divisors (see below), whose sum is σ = 2034979200. Its totient is φ = 912891024.

The previous prime is 1371473717. The next prime is 1371473731. The reversal of 1371473721 is 1273741731.

It is a happy number.

It is not a de Polignac number, because 1371473721 - 2² = 1371473717 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1371473711) 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 15 ways as a sum of consecutive naturals, for example, 21786 + ... + 56723.

It is an arithmetic number, because the mean of its divisors is an integer number (127186200).

Almost surely, 2^1371473721 is an apocalyptic number.

It is an amenable number.

1371473721 is a deficient number, since it is larger than the sum of its proper divisors (663505479).

1371473721 is an equidigital number, since it uses as much as digits as its factorization.

1371473721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79165 (or 79159 counting only the distinct ones).

The product of its digits is 24696, while the sum is 36.

The square root of 1371473721 is about 37033.4135747706. The cubic root of 1371473721 is about 1111.0386406841.

The spelling of 1371473721 in words is "one billion, three hundred seventy-one million, four hundred seventy-three thousand, seven hundred twenty-one".