21071742 has 16 divisors (see below), whose sum is σ = 42721680. Its totient is φ = 6927552.

The previous prime is 21071737. The next prime is 21071747. The reversal of 21071742 is 24717012.

It is an interprime number because it is at equal distance from previous prime (21071737) and next prime (21071747).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21071747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23617 + ... + 24492.

It is an arithmetic number, because the mean of its divisors is an integer number (2670105).

Almost surely, 2^21071742 is an apocalyptic number.

21071742 is an abundant number, since it is smaller than the sum of its proper divisors (21649938).

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

21071742 is a wasteful number, since it uses less digits than its factorization.

21071742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48187.

The product of its (nonzero) digits is 784, while the sum is 24.

The square root of 21071742 is about 4590.3967148821. The cubic root of 21071742 is about 276.2062363192.

Adding to 21071742 its reverse (24717012), we get a palindrome (45788754).

The spelling of 21071742 in words is "twenty-one million, seventy-one thousand, seven hundred forty-two".