21252274 has 4 divisors (see below), whose sum is σ = 31878414. Its totient is φ = 10626136.

The previous prime is 21252269. The next prime is 21252281. The reversal of 21252274 is 47225212.

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., 16443025 + 4809249 = 4055^2 + 2193^2 .

It is the 60-th Perrin number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5313067 + ... + 5313070.

Almost surely, 2^21252274 is an apocalyptic number.

21252274 is a deficient number, since it is larger than the sum of its proper divisors (10626140).

21252274 is a wasteful number, since it uses less digits than its factorization.

21252274 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10626139.

The product of its digits is 2240, while the sum is 25.

The square root of 21252274 is about 4610.0188719787. The cubic root of 21252274 is about 276.9927926287.

Adding to 21252274 its reverse (47225212), we get a palindrome (68477486).

The spelling of 21252274 in words is "twenty-one million, two hundred fifty-two thousand, two hundred seventy-four".