21443642 has 8 divisors (see below), whose sum is σ = 35089632. Its totient is φ = 9747100.

The previous prime is 21443629. The next prime is 21443657. The reversal of 21443642 is 24634412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 487334 + ... + 487377.

It is an arithmetic number, because the mean of its divisors is an integer number (4386204).

Almost surely, 2^21443642 is an apocalyptic number.

21443642 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21443642 is a deficient number, since it is larger than the sum of its proper divisors (13645990).

21443642 is a wasteful number, since it uses less digits than its factorization.

21443642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 974724.

The product of its digits is 4608, while the sum is 26.

The square root of 21443642 is about 4630.7280205169. The cubic root of 21443642 is about 277.8217116761.

The spelling of 21443642 in words is "twenty-one million, four hundred forty-three thousand, six hundred forty-two".