21702940 has 96 divisors (see below), whose sum is σ = 56448000. Its totient is φ = 6842880.

The previous prime is 21702937. The next prime is 21702949. The reversal of 21702940 is 4920712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21702949) 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 31 ways as a sum of consecutive naturals, for example, 108961 + ... + 109159.

It is an arithmetic number, because the mean of its divisors is an integer number (588000).

Almost surely, 2^21702940 is an apocalyptic number.

21702940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21702940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28224000).

21702940 is an abundant number, since it is smaller than the sum of its proper divisors (34745060).

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

21702940 is a wasteful number, since it uses less digits than its factorization.

21702940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275 (or 273 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 21702940 is about 4658.6414328643. The cubic root of 21702940 is about 278.9370412445.

The spelling of 21702940 in words is "twenty-one million, seven hundred two thousand, nine hundred forty".