721377673 has 4 divisors (see below), whose sum is σ = 723682708. Its totient is φ = 719072640.

The previous prime is 721377659. The next prime is 721377737. The reversal of 721377673 is 376773127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 376773127 = 101 ⋅3730427.

It can be written as a sum of positive squares in 2 ways, for example, as 264615289 + 456762384 = 16267^2 + 21372^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721377673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721377623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1152048 + ... + 1152673.

It is an arithmetic number, because the mean of its divisors is an integer number (180920677).

Almost surely, 2^721377673 is an apocalyptic number.

It is an amenable number.

721377673 is a deficient number, since it is larger than the sum of its proper divisors (2305035).

721377673 is a wasteful number, since it uses less digits than its factorization.

721377673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2305034.

The product of its digits is 259308, while the sum is 43.

The square root of 721377673 is about 26858.4748822415. The cubic root of 721377673 is about 896.8522434513.

The spelling of 721377673 in words is "seven hundred twenty-one million, three hundred seventy-seven thousand, six hundred seventy-three".