21226072 has 32 divisors (see below), whose sum is σ = 46955520. Its totient is φ = 8802720.

The previous prime is 21226063. The next prime is 21226087. The reversal of 21226072 is 27062212.

It is a super-2 number, since 2×21226072² = 901092265098368, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 4378 + ... + 7849.

It is an arithmetic number, because the mean of its divisors is an integer number (1467360).

Almost surely, 2^21226072 is an apocalyptic number.

It is an amenable number.

21226072 is an abundant number, since it is smaller than the sum of its proper divisors (25729448).

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

21226072 is a wasteful number, since it uses less digits than its factorization.

21226072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12271 (or 12267 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 21226072 is about 4607.1761416295. The cubic root of 21226072 is about 276.8789106993.

Adding to 21226072 its reverse (27062212), we get a palindrome (48288284).

The spelling of 21226072 in words is "twenty-one million, two hundred twenty-six thousand, seventy-two".