21442678 has 24 divisors (see below), whose sum is σ = 35963352. Its totient is φ = 9554112.

The previous prime is 21442667. The next prime is 21442699. The reversal of 21442678 is 87624412.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11401 + ... + 13147.

It is an arithmetic number, because the mean of its divisors is an integer number (1498473).

Almost surely, 2^21442678 is an apocalyptic number.

21442678 is a deficient number, since it is larger than the sum of its proper divisors (14520674).

21442678 is a wasteful number, since it uses less digits than its factorization.

21442678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1804 (or 1785 counting only the distinct ones).

The product of its digits is 21504, while the sum is 34.

The square root of 21442678 is about 4630.6239320420. The cubic root of 21442678 is about 277.8175484508.

The spelling of 21442678 in words is "twenty-one million, four hundred forty-two thousand, six hundred seventy-eight".