21900340 has 48 divisors (see below), whose sum is σ = 57343104. Its totient is φ = 6825600.

The previous prime is 21900313. The next prime is 21900341. The reversal of 21900340 is 4300912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21900341) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 5571 + ... + 8650.

It is an arithmetic number, because the mean of its divisors is an integer number (1194648).

Almost surely, 2^21900340 is an apocalyptic number.

21900340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21900340 is an abundant number, since it is smaller than the sum of its proper divisors (35442764).

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

21900340 is a wasteful number, since it uses less digits than its factorization.

21900340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14248 (or 14246 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 21900340 is about 4679.7799093547. The cubic root of 21900340 is about 279.7801846209.

The spelling of 21900340 in words is "twenty-one million, nine hundred thousand, three hundred forty".