21401942 has 16 divisors (see below), whose sum is σ = 34959600. Its totient is φ = 9787680.

The previous prime is 21401927. The next prime is 21401951. The reversal of 21401942 is 24910412.

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, 8609 + ... + 10812.

It is an arithmetic number, because the mean of its divisors is an integer number (2184975).

Almost surely, 2^21401942 is an apocalyptic number.

21401942 is a deficient number, since it is larger than the sum of its proper divisors (13557658).

21401942 is a wasteful number, since it uses less digits than its factorization.

21401942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19471.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 21401942 is about 4626.2232976803. The cubic root of 21401942 is about 277.6415077859.

The spelling of 21401942 in words is "twenty-one million, four hundred one thousand, nine hundred forty-two".