21142354 has 4 divisors (see below), whose sum is σ = 31713534. Its totient is φ = 10571176.

The previous prime is 21142351. The next prime is 21142361. The reversal of 21142354 is 45324112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 16200625 + 4941729 = 4025^2 + 2223^2 .

It is a super-2 number, since 2×21142354² = 893998265322632, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21142351) by changing a digit.

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 as a sum of consecutive naturals, namely, 5285587 + ... + 5285590.

Almost surely, 2^21142354 is an apocalyptic number.

21142354 is a deficient number, since it is larger than the sum of its proper divisors (10571180).

21142354 is a wasteful number, since it uses less digits than its factorization.

21142354 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10571179.

The product of its digits is 960, while the sum is 22.

The square root of 21142354 is about 4598.0815564755. The cubic root of 21142354 is about 276.5144172891.

Adding to 21142354 its reverse (45324112), we get a palindrome (66466466).

The spelling of 21142354 in words is "twenty-one million, one hundred forty-two thousand, three hundred fifty-four".