21723357 has 8 divisors (see below), whose sum is σ = 29051776. Its totient is φ = 14438592.

The previous prime is 21723347. The next prime is 21723367. The reversal of 21723357 is 75332712.

It is an interprime number because it is at equal distance from previous prime (21723347) and next prime (21723367).

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

It is not a de Polignac number, because 21723357 - 2⁸ = 21723101 is a prime.

It is a super-4 number, since 4×21723357⁴ (a number of 30 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21723307) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9733 + ... + 11754.

It is an arithmetic number, because the mean of its divisors is an integer number (3631472).

Almost surely, 2^21723357 is an apocalyptic number.

It is an amenable number.

21723357 is a deficient number, since it is larger than the sum of its proper divisors (7328419).

21723357 is a wasteful number, since it uses less digits than its factorization.

21723357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21827.

The product of its digits is 8820, while the sum is 30.

The square root of 21723357 is about 4660.8322218248. The cubic root of 21723357 is about 279.0244836622.

The spelling of 21723357 in words is "twenty-one million, seven hundred twenty-three thousand, three hundred fifty-seven".