21923340 has 48 divisors (see below), whose sum is σ = 64619520. Its totient is φ = 5538240.

The previous prime is 21923311. The next prime is 21923381. The reversal of 21923340 is 4332912.

It is a self number, because there is not a number n which added to its sum of digits gives 21923340.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8476 + ... + 10755.

It is an arithmetic number, because the mean of its divisors is an integer number (1346240).

Almost surely, 2^21923340 is an apocalyptic number.

21923340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21923340 is an abundant number, since it is smaller than the sum of its proper divisors (42696180).

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

21923340 is a wasteful number, since it uses less digits than its factorization.

21923340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19262 (or 19260 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 21923340 is about 4682.2366450234. The cubic root of 21923340 is about 279.8780931902.

The spelling of 21923340 in words is "twenty-one million, nine hundred twenty-three thousand, three hundred forty".