21623738 has 8 divisors (see below), whose sum is σ = 32599200. Its totient is φ = 10757340.

The previous prime is 21623731. The next prime is 21623773. The reversal of 21623738 is 83732612.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (21623731) 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, 26768 + ... + 27563.

It is an arithmetic number, because the mean of its divisors is an integer number (4074900).

Almost surely, 2^21623738 is an apocalyptic number.

21623738 is a deficient number, since it is larger than the sum of its proper divisors (10975462).

21623738 is a wasteful number, since it uses less digits than its factorization.

21623738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54532.

The product of its digits is 12096, while the sum is 32.

The square root of 21623738 is about 4650.1331163742. The cubic root of 21623738 is about 278.5973130702.

The spelling of 21623738 in words is "twenty-one million, six hundred twenty-three thousand, seven hundred thirty-eight".