21623120 has 40 divisors (see below), whose sum is σ = 51901440. Its totient is φ = 8369280.

The previous prime is 21623101. The next prime is 21623131. The reversal of 21623120 is 2132612.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1880 + ... + 6839.

It is an arithmetic number, because the mean of its divisors is an integer number (1297536).

Almost surely, 2^21623120 is an apocalyptic number.

21623120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21623120 is an abundant number, since it is smaller than the sum of its proper divisors (30278320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21623120 is a wasteful number, since it uses less digits than its factorization.

21623120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8763 (or 8757 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21623120 is about 4650.0666661888. The cubic root of 21623120 is about 278.5946589688.

Adding to 21623120 its reverse (2132612), we get a palindrome (23755732).

The spelling of 21623120 in words is "twenty-one million, six hundred twenty-three thousand, one hundred twenty".