21581674 has 4 divisors (see below), whose sum is σ = 32372514. Its totient is φ = 10790836.

The previous prime is 21581671. The next prime is 21581683. The reversal of 21581674 is 47618512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 15155449 + 6426225 = 3893^2 + 2535^2 .

It is not an unprimeable number, because it can be changed into a prime (21581671) 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 as a sum of consecutive naturals, namely, 5395417 + ... + 5395420.

Almost surely, 2^21581674 is an apocalyptic number.

21581674 is a deficient number, since it is larger than the sum of its proper divisors (10790840).

21581674 is a wasteful number, since it uses less digits than its factorization.

21581674 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10790839.

The product of its digits is 13440, while the sum is 34.

The square root of 21581674 is about 4645.6080334010. The cubic root of 21581674 is about 278.4165468459.

The spelling of 21581674 in words is "twenty-one million, five hundred eighty-one thousand, six hundred seventy-four".