21221274 has 32 divisors (see below), whose sum is σ = 43997184. Its totient is φ = 6819120.

The previous prime is 21221273. The next prime is 21221279. The reversal of 21221274 is 47212212.

It is a self number, because there is not a number n which added to its sum of digits gives 21221274.

It is not an unprimeable number, because it can be changed into a prime (21221273) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20919 + ... + 21909.

It is an arithmetic number, because the mean of its divisors is an integer number (1374912).

Almost surely, 2^21221274 is an apocalyptic number.

21221274 is an abundant number, since it is smaller than the sum of its proper divisors (22775910).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21221274 is a wasteful number, since it uses less digits than its factorization.

21221274 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1122.

The product of its digits is 448, while the sum is 21.

The square root of 21221274 is about 4606.6554027841. The cubic root of 21221274 is about 276.8580469690.

Adding to 21221274 its reverse (47212212), we get a palindrome (68433486).

The spelling of 21221274 in words is "twenty-one million, two hundred twenty-one thousand, two hundred seventy-four".