21127842 has 24 divisors (see below), whose sum is σ = 45961344. Its totient is φ = 7014264.

The previous prime is 21127819. The next prime is 21127853. The reversal of 21127842 is 24872112.

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, 2503 + ... + 6965.

It is an arithmetic number, because the mean of its divisors is an integer number (1915056).

Almost surely, 2^21127842 is an apocalyptic number.

21127842 is an abundant number, since it is smaller than the sum of its proper divisors (24833502).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21127842 is a wasteful number, since it uses less digits than its factorization.

21127842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4734 (or 4731 counting only the distinct ones).

The product of its digits is 1792, while the sum is 27.

The square root of 21127842 is about 4596.5032361568. The cubic root of 21127842 is about 276.4511367971.

Adding to 21127842 its reverse (24872112), we get a palindrome (45999954).

It can be divided in two parts, 2 and 1127842, that added together give a square (1127844 = 1062²).

The spelling of 21127842 in words is "twenty-one million, one hundred twenty-seven thousand, eight hundred forty-two".