21251042 has 8 divisors (see below), whose sum is σ = 32044032. Its totient is φ = 10569700.

The previous prime is 21251023. The next prime is 21251053. The reversal of 21251042 is 24015212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21251042.

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, 27434 + ... + 28197.

It is an arithmetic number, because the mean of its divisors is an integer number (4005504).

Almost surely, 2^21251042 is an apocalyptic number.

21251042 is a deficient number, since it is larger than the sum of its proper divisors (10792990).

21251042 is a wasteful number, since it uses less digits than its factorization.

21251042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55824.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 21251042 is about 4609.8852480295. The cubic root of 21251042 is about 276.9874400766.

Adding to 21251042 its reverse (24015212), we get a palindrome (45266254).

The spelling of 21251042 in words is "twenty-one million, two hundred fifty-one thousand, forty-two".