21701940 has 48 divisors (see below), whose sum is σ = 65442048. Its totient is φ = 5341824.

The previous prime is 21701879. The next prime is 21701941. The reversal of 21701940 is 4910712.

It is a self number, because there is not a number n which added to its sum of digits gives 21701940.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21701941) 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, 13132 + ... + 14691.

It is an arithmetic number, because the mean of its divisors is an integer number (1363376).

Almost surely, 2^21701940 is an apocalyptic number.

21701940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21701940 is an abundant number, since it is smaller than the sum of its proper divisors (43740108).

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

21701940 is a wasteful number, since it uses less digits than its factorization.

21701940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27848 (or 27846 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 24.

The square root of 21701940 is about 4658.5341042006. The cubic root of 21701940 is about 278.9327570120.

The spelling of 21701940 in words is "twenty-one million, seven hundred one thousand, nine hundred forty".