21403274 has 4 divisors (see below), whose sum is σ = 32104914. Its totient is φ = 10701636.

The previous prime is 21403273. The next prime is 21403303. The reversal of 21403274 is 47230412.

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., 17581249 + 3822025 = 4193^2 + 1955^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21403273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5350817 + ... + 5350820.

Almost surely, 2^21403274 is an apocalyptic number.

21403274 is a deficient number, since it is larger than the sum of its proper divisors (10701640).

21403274 is a wasteful number, since it uses less digits than its factorization.

21403274 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10701639.

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 21403274 is about 4626.3672573630. The cubic root of 21403274 is about 277.6472675563.

Adding to 21403274 its reverse (47230412), we get a palindrome (68633686).

The spelling of 21403274 in words is "twenty-one million, four hundred three thousand, two hundred seventy-four".