21088642 has 8 divisors (see below), whose sum is σ = 31874832. Its totient is φ = 10463700.

The previous prime is 21088621. The next prime is 21088667. The reversal of 21088642 is 24688012.

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, 39984 + ... + 40507.

It is an arithmetic number, because the mean of its divisors is an integer number (3984354).

Almost surely, 2^21088642 is an apocalyptic number.

21088642 is a deficient number, since it is larger than the sum of its proper divisors (10786190).

21088642 is a wasteful number, since it uses less digits than its factorization.

21088642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80624.

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 21088642 is about 4592.2371454445. The cubic root of 21088642 is about 276.2800577437.

The spelling of 21088642 in words is "twenty-one million, eighty-eight thousand, six hundred forty-two".