21126742 has 64 divisors (see below), whose sum is σ = 41932800. Its totient is φ = 7916832.

The previous prime is 21126739. The next prime is 21126757. The reversal of 21126742 is 24762112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 205063 + ... + 205165.

It is an arithmetic number, because the mean of its divisors is an integer number (655200).

Almost surely, 2^21126742 is an apocalyptic number.

21126742 is a deficient number, since it is larger than the sum of its proper divisors (20806058).

21126742 is a wasteful number, since it uses less digits than its factorization.

21126742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162 (or 148 counting only the distinct ones).

The product of its digits is 1344, while the sum is 25.

The square root of 21126742 is about 4596.3835784234. The cubic root of 21126742 is about 276.4463389964.

Adding to 21126742 its reverse (24762112), we get a palindrome (45888854).

The spelling of 21126742 in words is "twenty-one million, one hundred twenty-six thousand, seven hundred forty-two".