21022472 has 32 divisors (see below), whose sum is σ = 41951520. Its totient is φ = 9841920.

The previous prime is 21022471. The next prime is 21022517. The reversal of 21022472 is 27422012.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21022471) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44783 + ... + 45249.

It is an arithmetic number, because the mean of its divisors is an integer number (1310985).

Almost surely, 2^21022472 is an apocalyptic number.

It is an amenable number.

21022472 is a deficient number, since it is larger than the sum of its proper divisors (20929048).

21022472 is a wasteful number, since it uses less digits than its factorization.

21022472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 821 (or 817 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 20.

The square root of 21022472 is about 4585.0269355806. The cubic root of 21022472 is about 275.9907929436.

Adding to 21022472 its reverse (27422012), we get a palindrome (48444484).

The spelling of 21022472 in words is "twenty-one million, twenty-two thousand, four hundred seventy-two".