21772723 has 8 divisors (see below), whose sum is σ = 24973920. Its totient is φ = 18594240.

The previous prime is 21772691. The next prime is 21772741. The reversal of 21772723 is 32727712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21772723 - 2⁵ = 21772691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21772123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3568 + ... + 7501.

It is an arithmetic number, because the mean of its divisors is an integer number (3121740).

Almost surely, 2^21772723 is an apocalyptic number.

21772723 is a deficient number, since it is larger than the sum of its proper divisors (3201197).

21772723 is a wasteful number, since it uses less digits than its factorization.

21772723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11357.

The product of its digits is 8232, while the sum is 31.

The square root of 21772723 is about 4666.1250519033. The cubic root of 21772723 is about 279.2356833989.

It can be divided in two parts, 2177 and 2723, that added together give a square (4900 = 70²).

The spelling of 21772723 in words is "twenty-one million, seven hundred seventy-two thousand, seven hundred twenty-three".