721328149 has 4 divisors (see below), whose sum is σ = 721493536. Its totient is φ = 721162764.

The previous prime is 721328131. The next prime is 721328161. The reversal of 721328149 is 941823127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 941823127 = 7 ⋅134546161.

It is a cyclic number.

It is not a de Polignac number, because 721328149 - 2⁷ = 721328021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721328189) 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, 75969 + ... + 84934.

It is an arithmetic number, because the mean of its divisors is an integer number (180373384).

Almost surely, 2^721328149 is an apocalyptic number.

It is an amenable number.

721328149 is a deficient number, since it is larger than the sum of its proper divisors (165387).

721328149 is a wasteful number, since it uses less digits than its factorization.

721328149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165386.

The product of its digits is 24192, while the sum is 37.

The square root of 721328149 is about 26857.5529227813. The cubic root of 721328149 is about 896.8317194232.

The spelling of 721328149 in words is "seven hundred twenty-one million, three hundred twenty-eight thousand, one hundred forty-nine".