21155342 has 16 divisors (see below), whose sum is σ = 35099232. Its totient is φ = 9499680.

The previous prime is 21155339. The next prime is 21155363. The reversal of 21155342 is 24355112.

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, 10034 + ... + 11957.

It is an arithmetic number, because the mean of its divisors is an integer number (2193702).

Almost surely, 2^21155342 is an apocalyptic number.

21155342 is a deficient number, since it is larger than the sum of its proper divisors (13943890).

21155342 is a wasteful number, since it uses less digits than its factorization.

21155342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22043.

The product of its digits is 1200, while the sum is 23.

The square root of 21155342 is about 4599.4936677856. The cubic root of 21155342 is about 276.5710277324.

The spelling of 21155342 in words is "twenty-one million, one hundred fifty-five thousand, three hundred forty-two".