84723721 has 4 divisors (see below), whose sum is σ = 85103872. Its totient is φ = 84343572.

The previous prime is 84723707. The next prime is 84723731. The reversal of 84723721 is 12732748.

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.

It is a cyclic number.

It is not a de Polignac number, because 84723721 - 2⁹ = 84723209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (84723701) 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, 189741 + ... + 190186.

It is an arithmetic number, because the mean of its divisors is an integer number (21275968).

Almost surely, 2^84723721 is an apocalyptic number.

It is an amenable number.

84723721 is a deficient number, since it is larger than the sum of its proper divisors (380151).

84723721 is a wasteful number, since it uses less digits than its factorization.

84723721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380150.

The product of its digits is 18816, while the sum is 34.

The square root of 84723721 is about 9204.5489297412. The cubic root of 84723721 is about 439.2060769390.

The spelling of 84723721 in words is "eighty-four million, seven hundred twenty-three thousand, seven hundred twenty-one".