1373267721 has 16 divisors (see below), whose sum is σ = 2093856128. Its totient is φ = 784252800.

The previous prime is 1373267719. The next prime is 1373267741. The reversal of 1373267721 is 1277623731.

It is not a de Polignac number, because 1373267721 - 2¹ = 1373267719 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1373267721.

It is not an unprimeable number, because it can be changed into a prime (1373267741) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17781 + ... + 55341.

It is an arithmetic number, because the mean of its divisors is an integer number (130866008).

Almost surely, 2^1373267721 is an apocalyptic number.

It is an amenable number.

1373267721 is a deficient number, since it is larger than the sum of its proper divisors (720588407).

1373267721 is a wasteful number, since it uses less digits than its factorization.

1373267721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39312.

The product of its digits is 74088, while the sum is 39.

The square root of 1373267721 is about 37057.6270287238. The cubic root of 1373267721 is about 1111.5228727990.

The spelling of 1373267721 in words is "one billion, three hundred seventy-three million, two hundred sixty-seven thousand, seven hundred twenty-one".