21240274 has 8 divisors (see below), whose sum is σ = 34756848. Its totient is φ = 9654660.

The previous prime is 21240253. The next prime is 21240283. The reversal of 21240274 is 47204212.

It is a happy number.

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

It is a super-2 number, since 2×21240274² = 902298479190152, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (22), and also a Moran number because the ratio is a prime number: 965467 = 21240274 / (2 + 1 + 2 + 4 + 0 + 2 + 7 + 4).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 482712 + ... + 482755.

It is an arithmetic number, because the mean of its divisors is an integer number (4344606).

Almost surely, 2^21240274 is an apocalyptic number.

21240274 is a deficient number, since it is larger than the sum of its proper divisors (13516574).

21240274 is a wasteful number, since it uses less digits than its factorization.

21240274 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 965480.

The product of its (nonzero) digits is 896, while the sum is 22.

The square root of 21240274 is about 4608.7171750933. The cubic root of 21240274 is about 276.9406485724.

Adding to 21240274 its reverse (47204212), we get a palindrome (68444486).

The spelling of 21240274 in words is "twenty-one million, two hundred forty thousand, two hundred seventy-four".