21739874 has 8 divisors (see below), whose sum is σ = 35118300. Its totient is φ = 10033776.

The previous prime is 21739873. The next prime is 21739877. The reversal of 21739874 is 47893712.

It can be written as a sum of positive squares in 2 ways, for example, as 19936225 + 1803649 = 4465^2 + 1343^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21739873) 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 3 ways as a sum of consecutive naturals, for example, 418049 + ... + 418100.

Almost surely, 2^21739874 is an apocalyptic number.

21739874 is a deficient number, since it is larger than the sum of its proper divisors (13378426).

21739874 is a wasteful number, since it uses less digits than its factorization.

21739874 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 836164.

The product of its digits is 84672, while the sum is 41.

The square root of 21739874 is about 4662.6037790059. The cubic root of 21739874 is about 279.0951829845.

The spelling of 21739874 in words is "twenty-one million, seven hundred thirty-nine thousand, eight hundred seventy-four".